sky at night - april 2014
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the biggest name in astronomy
solar system hotspot
New insights into the volcanic moon Io
preserving the night
The UK’s newest Dark Sky areas uncovered
aPriL 2014 #107www.skyatnightmagazine.com
see mars at its brightest and best
Discover why this once wet world is now a desert
the worLD’s
biggest & best
night-sky guiDe
Sky at Night
life in low
earth orbitThe challenges of living and working on the ISS
scope test
light unlocked
steady on
The new instruments that will reveal the secrets of starlight
Expert techniques to hold binoculars higher for longer
also in
this issue
Meade’s new LX600 telescope with automatic guiding built in
planet
return oF thered
create a stunning moon mosaic image
the biggest name in astronomy
solar system hotspot
New insights into the volcanic moon Io
preserving the night
The UK’s newest Dark Sky areas uncovered
aPriL 2014 #107www.skyatnightmagazine.com
see mars at its brightest and best
Discover why this once wet world is now a desert
the worLD’s
biggest & best
night-sky guiDe
Sky at Night
life in low
earth orbitThe challenges of living and working on the ISS
scope test
light unlocked
steady on
The new instruments that will reveal the secrets of starlight
Expert techniques to hold binoculars higher for longer
also in
this issue
Meade’s new LX600 telescope with automatic guiding built in
planet
return oF thered
create a stunning moon mosaic image
TECHNOLOGICALLYSUPERIOR
Celestron’s innovative new SkyQ Link WiFi Module turns your iPhone or iPad into your own personal planetarium and observatory!
Automatically align your Celestron telescope with our StarSense Accessory!The revolutionary technology in the award-winning SkyProdigy telescope is now available for almost every Celestron computerised telescope.
Celestron®, SkyQTM and StarSenseTM are trademarks or registered trademarks of Celestron Acquisition, LLC in the United States and in dozens of other countries around the world.
All rights reserved. David Hinds Ltd is an authorised distributor and reseller of Celestron products. The iPhone® and iPad® are trademarks of Apple Inc., registered in the U.S. and other countries.
AppStore is a trademark of Apple Inc.
www.celestron.uk.comImagine the possibilities
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Align and control your Celestron telescope wirelessly using your iPhone or iPad!
and specialist dealers nationwide
Special Offer! Big Savings now available on
all NexStar SE telescopes.Contact your local Celestron Dealer
for more information.
TECHNOLOGICALLYSUPERIOR
Celestron’s innovative new SkyQ Link WiFi Module turns your iPhone or iPad into your own personal planetarium and observatory!
Automatically align your Celestron telescope with our StarSense Accessory!The revolutionary technology in the award-winning SkyProdigy telescope is now available for almost every Celestron computerised telescope.
Celestron®, SkyQTM and StarSenseTM are trademarks or registered trademarks of Celestron Acquisition, LLC in the United States and in dozens of other countries around the world.
All rights reserved. David Hinds Ltd is an authorised distributor and reseller of Celestron products. The iPhone® and iPad® are trademarks of Apple Inc., registered in the U.S. and other countries.
AppStore is a trademark of Apple Inc.
www.celestron.uk.comImagine the possibilities
StarSenseAccessory
F1 Telescopes
Sittingbourne
01795 432702
Green Witch (North)
West Yorkshire
01924 477719
Astronomia
Dorking
01306 640714
Green Witch (South)
Bedfordshire
01767 677025
Widescreen Centre
Central London
020 7935 2580
SkyQ LinkWiFi Module
Align and control your Celestron telescope wirelessly using your iPhone or iPad!
and specialist dealers nationwide
Special Offer! Big Savings now available on
all NexStar SE telescopes.Contact your local Celestron Dealer
for more information.
Letter from the editor APRIL 03
skyatnightmagazine.com 2014
Welcome
HoW to contact usSubscriptions, binders, CD cases and back issues0844 844 0254 Mon to Fri 8am to 8pm; Sat 9am to 1pm for ordersEditorial enquiries0117 314 7411 9.30am to 5.30pm, Mon to Fri Advertising enquiries0117 314 8365
Subscription email enquiries skyatnight@servicehelpline.co.ukEditorial enquiriescontactus@skyatnightmagazine.comApp enquirieshttp://apps.immediate.co.uk/support immediateapps@servicehelpline.co.uk
Editorial enquiries BBC Sky at Night Magazine, Immediate Media Co Bristol Ltd, Tower House, Fairfax Street, Bristol, BS1 3BN
stepHen tonkin
Binocular oBserver
Stephen dispenses his top tips on how to get steadier
views when observing with binoculars in this month’s How to. Page 90
Will Gater
astronomy author
Will marks the invention of the spectroscope with a look
at how its modern-day equivalents continue to aid astronomers. Page 73
Martin leWis
Planetary imager
Martin explains how to make the most of the
Red Planet its brightest and best for the current apparition. Page 41
sean Blair
sPace writer
Sean tackles a planetary murder mystery:
what happened to the atmosphere of the Red Planet? Page 34
ps Next issue goes on sale 17 April.
this month’s contributors include...
Chris Bramley editor
Everything you need to know about Mars’s opposition
sky at night lots of ways to enjoy the night sky...
poDcast
The BBC Sky at Night Magazine team discuss the latest astro news in our monthly podcast
Follow @skyatnightmag to keep up with the latest space stories and tell us what you think
online Visit our website for reviews, competitions, astrophotos, observing guides and our forum
television Find out what The Sky at Night team will be exploring in this month’s episode on page 19
ipaD
Get each month’s issue on your iPad, now with bonus video and extra images
All the details of our latest issue, plus news from the magazine and updates to our website
how to capture the images, then process and stitch them together to create a fnal masterpiece rich in detail. And on page 73, there’s the fascinating tale of one of astronomy’s most unsung tools – the spectroscope. To tie in with the 200th anniversary of its invention, we look at how this instrument continues to unlock the secrets of starlight.
Enjoy the issue!
From Mariner 4’s frst visit in 1964 to Curiosity’s present-day explorations, Mars is the most visited destination for space probes. Now two new spacecraft are on their way to the Red Planet to uncover
more about its atmosphere. The data NASA’s MAVEN and India’s Mars Orbiter Mission will send back is set to give us new insights into the planet’s protective envelope, why it disappeared and the impact this had on the planet’s potentially life-sustaining supply of water. Find out more on page 34.
Though Mars’s dust storms and carbon dioxide ice are visible with a telescope, its tenuous atmosphere is one thing you won’t see, even with the planet at its brightest this month. April’s opposition is a great time to see the raft of details visible on the planet. From the dark markings that break up Mars’s red-hued globe to the white polar caps, Martin Lewis’s feature on page 41 shows you how to get the most out of observing and imaging the Red Planet this apparition. You’ll also fnd expert advice on imaging Mars on page 64, and on page 93, Carol Lakomiak explains how to sketch the planet.
Elsewhere this month, on page 80 you’ll fnd a detailed guide to creating a lunar mosaic. Pete Lawrence takes you through
Letter from the editor APRIL 03
skyatnightmagazine.com 2014
Welcome
HoW to contact usSubscriptions, binders, CD cases and back issues0844 844 0254 Mon to Fri 8am to 8pm; Sat 9am to 1pm for ordersEditorial enquiries0117 314 7411 9.30am to 5.30pm, Mon to Fri Advertising enquiries0117 314 8365
Subscription email enquiries skyatnight@servicehelpline.co.ukEditorial enquiriescontactus@skyatnightmagazine.comApp enquirieshttp://apps.immediate.co.uk/support immediateapps@servicehelpline.co.uk
Editorial enquiries BBC Sky at Night Magazine, Immediate Media Co Bristol Ltd, Tower House, Fairfax Street, Bristol, BS1 3BN
stepHen tonkin
Binocular oBserver
Stephen dispenses his top tips on how to get steadier
views when observing with binoculars in this month’s How to. Page 90
Will Gater
astronomy author
Will marks the invention of the spectroscope with a look
at how its modern-day equivalents continue to aid astronomers. Page 73
Martin leWis
Planetary imager
Martin explains how to make the most of the
Red Planet its brightest and best for the current apparition. Page 41
sean Blair
sPace writer
Sean tackles a planetary murder mystery:
what happened to the atmosphere of the Red Planet? Page 34
ps Next issue goes on sale 17 April.
this month’s contributors include...
Chris Bramley editor
Everything you need to know about Mars’s opposition
sky at night lots of ways to enjoy the night sky...
poDcast
The BBC Sky at Night Magazine team discuss the latest astro news in our monthly podcast
Follow @skyatnightmag to keep up with the latest space stories and tell us what you think
online Visit our website for reviews, competitions, astrophotos, observing guides and our forum
television Find out what The Sky at Night team will be exploring in this month’s episode on page 19
ipaD
Get each month’s issue on your iPad, now with bonus video and extra images
All the details of our latest issue, plus news from the magazine and updates to our website
how to capture the images, then process and stitch them together to create a fnal masterpiece rich in detail. And on page 73, there’s the fascinating tale of one of astronomy’s most unsung tools – the spectroscope. To tie in with the 200th anniversary of its invention, we look at how this instrument continues to unlock the secrets of starlight.
Enjoy the issue!
From Mariner 4’s frst visit in 1964 to Curiosity’s present-day explorations, Mars is the most visited destination for space probes. Now two new spacecraft are on their way to the Red Planet to uncover
more about its atmosphere. The data NASA’s MAVEN and India’s Mars Orbiter Mission will send back is set to give us new insights into the planet’s protective envelope, why it disappeared and the impact this had on the planet’s potentially life-sustaining supply of water. Find out more on page 34.
Though Mars’s dust storms and carbon dioxide ice are visible with a telescope, its tenuous atmosphere is one thing you won’t see, even with the planet at its brightest this month. April’s opposition is a great time to see the raft of details visible on the planet. From the dark markings that break up Mars’s red-hued globe to the white polar caps, Martin Lewis’s feature on page 41 shows you how to get the most out of observing and imaging the Red Planet this apparition. You’ll also fnd expert advice on imaging Mars on page 64, and on page 93, Carol Lakomiak explains how to sketch the planet.
Elsewhere this month, on page 80 you’ll fnd a detailed guide to creating a lunar mosaic. Pete Lawrence takes you through
04
skyatnightmagazine.com 2014
mosaicing the moon80
mars at opposition41
First Light102
80
On the cOver
features
34
90
16
66
98
regulars
Inthemagazine New to astroNomy?See The guide on page 88 and our online glossary
at www.skyatnightmagazine.com/dictionary
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06Eye on the skyStunning new images of space.
34 Mars’s missing atmosphere
The greatest whodunnit of them all: we explore
the mystery of the disappearing atmosphere.
41 Mars at oppositionThe ultimate guide to viewing and imaging
the Red Planet as it comes to opposition.
66 Dark skies recognisedHow two more UK sites gained Dark Sky status.
73 Unlocking the secrets of light
How the humble spectroscope will lead the James
Webb Space Telescope into a new era of astronomy.
80 Mosaicing the MoonAll you need to know to create your frst lunar
mosaic, from image acquisition to completion.
73
88Skills88The guide The Local Group of galaxies.
90How to Get steadier binocular views.
93Sketching Mars at opposition.
95Scope Doctor
97ReviewsFirst Light
98 Meade LX600-ACF
12-inch Schmidt-Cassegrain.
102 William Optics GTF 102
fve-element astrograph.
Tried & Tested106QSI 683 WSG-8 CCD camera.
110Books 112Gear
114What I really want to know is…What is life like on the ISS?
11Bulletin
19What’s on
21A passion for spaceSky at Night presenter Maggie
Aderin-Pocock tells us what
we can learn from the sounds of space.
23Jon CulshawJon’s off-world travelogue continues.
24sUBscriBe get your issues at a discount
26Interactive
28Hotshots
51the sky iN
aPriL Your 15-page guide to the
night sky featuring the top
sights, an all-sky chart, a
deep-sky tour and more…
114
51
NEW
04
skyatnightmagazine.com 2014
mosaicing the moon80
mars at opposition41
First Light102
80
On the cOver
features
34
90
16
66
98
regulars
Inthemagazine New to astroNomy?See The guide on page 88 and our online glossary
at www.skyatnightmagazine.com/dictionary
co
ver
: th
ink
sto
ck
. n
asa
, th
is p
ag
e: d
am
ian
pea
ch
, pe
te l
aw
ren
ce,
ww
w.t
hes
ecre
tstu
dio
.net
06Eye on the skyStunning new images of space.
34 Mars’s missing atmosphere
The greatest whodunnit of them all: we explore
the mystery of the disappearing atmosphere.
41 Mars at oppositionThe ultimate guide to viewing and imaging
the Red Planet as it comes to opposition.
66 Dark skies recognisedHow two more UK sites gained Dark Sky status.
73 Unlocking the secrets of light
How the humble spectroscope will lead the James
Webb Space Telescope into a new era of astronomy.
80 Mosaicing the MoonAll you need to know to create your frst lunar
mosaic, from image acquisition to completion.
73
88Skills88The guide The Local Group of galaxies.
90How to Get steadier binocular views.
93Sketching Mars at opposition.
95Scope Doctor
97ReviewsFirst Light
98 Meade LX600-ACF
12-inch Schmidt-Cassegrain.
102 William Optics GTF 102
fve-element astrograph.
Tried & Tested106QSI 683 WSG-8 CCD camera.
110Books 112Gear
114What I really want to know is…What is life like on the ISS?
11Bulletin
19What’s on
21A passion for spaceSky at Night presenter Maggie
Aderin-Pocock tells us what
we can learn from the sounds of space.
23Jon CulshawJon’s off-world travelogue continues.
24sUBscriBe get your issues at a discount
26Interactive
28Hotshots
51the sky iN
aPriL Your 15-page guide to the
night sky featuring the top
sights, an all-sky chart, a
deep-sky tour and more…
114
51
NEW
skyatnightmagazine.com 2012 skyatnightmagazine.com 2012
aVaiLaBLe noW on itUnes – onLy £3.99 to download visit www.skyatnightmagazine.com/man-in-space-ipad-app
the Man In Space app is more than a digital book – it’s a complete multimedia experience. tap the screen to play videos, rotate spacecraft views and bring interactive
elements into play. you’ll never feel closer to being in space.
MAN IN SPACE iPAD APPcelebrate 50 years of mankind’s adventure in space
this app features: 3D views of legendary spacecraft, allowing you to examine them from different angles themed photo galleries featuring amazing images historic video footage interactive diagrams 360º panoramic views of the moon a foreword by sir patrick moore
skyatnightmagazine.com 2012 skyatnightmagazine.com 2012
aVaiLaBLe noW on itUnes – onLy £3.99 to download visit www.skyatnightmagazine.com/man-in-space-ipad-app
the Man In Space app is more than a digital book – it’s a complete multimedia experience. tap the screen to play videos, rotate spacecraft views and bring interactive
elements into play. you’ll never feel closer to being in space.
MAN IN SPACE iPAD APPcelebrate 50 years of mankind’s adventure in space
this app features: 3D views of legendary spacecraft, allowing you to examine them from different angles themed photo galleries featuring amazing images historic video footage interactive diagrams 360º panoramic views of the moon a foreword by sir patrick moore
There are more than 100 asteroids visible in this image from NASA’s Wide-feld Infrared Survey Explorer (WISE). Although it is not easy to spot them all, some do stand out as a series of dots – like asteroid (2415) Ganesa, which can be seen just left of centre.
The asteroids, located within our Solar System, sit against an infrared view of a background star feld around 30 lightyears across. Along with bright clusters, like NGC
2158 to the centre right, this star feld is home to vast, billowing clouds of gas and dust revealed in infrared light. The data used to create this image was captured during WISE’s primary all-sky survey. The spacecraft went into hibernation shortly afterwards in 2011 but was revived last year, renamed NEOWISE and commissioned to hunt down more of the elusive space rocks captured so brilliantly in this image.
WIdE-fIEld INfrArEd SurvEy ExplOrEr, 23 JANuAry 2014
Against gas clouds and star clusters, an armada of space rocks sails silently through the darkness
amassAsteroids
There are more than 100 asteroids visible in this image from NASA’s Wide-feld Infrared Survey Explorer (WISE). Although it is not easy to spot them all, some do stand out as a series of dots – like asteroid (2415) Ganesa, which can be seen just left of centre.
The asteroids, located within our Solar System, sit against an infrared view of a background star feld around 30 lightyears across. Along with bright clusters, like NGC
2158 to the centre right, this star feld is home to vast, billowing clouds of gas and dust revealed in infrared light. The data used to create this image was captured during WISE’s primary all-sky survey. The spacecraft went into hibernation shortly afterwards in 2011 but was revived last year, renamed NEOWISE and commissioned to hunt down more of the elusive space rocks captured so brilliantly in this image.
WIdE-fIEld INfrArEd SurvEy ExplOrEr, 23 JANuAry 2014
Against gas clouds and star clusters, an armada of space rocks sails silently through the darkness
amassAsteroids
skyatnightmagazine.com 2014
▲ A grand spiral in the southern sky
HubblE SpACE TElESCOpE 9 JANuAry 2014
This image of M83, the Southern pinwheel galaxy, shows off a beautiful range of vivid hues. The reason for such vibrancy: a vast number of stars in the throngs of birth and death. M83 is a barred spiral, the same type of galaxy as the Milky Way, but unlike our home in space it has a ‘double nucleus’ at its heart.
Engaging rings
CASSINI SpACECrAfT 20 JANuAry 2014
Saturn’s famous ring system takes centre stage in this infrared image from Cassini. Taken from a distance of 1.1 million km, it reveals a bright spot in the rings – look for it just left of centre – called an opposition surge. This occurs when the Sun is directly behind the probe. Astronomers will analyse the size and magnitude of the surge to learn more about the properties of the ring particles.
skyatnightmagazine.com 2014
▲ A grand spiral in the southern sky
HubblE SpACE TElESCOpE 9 JANuAry 2014
This image of M83, the Southern pinwheel galaxy, shows off a beautiful range of vivid hues. The reason for such vibrancy: a vast number of stars in the throngs of birth and death. M83 is a barred spiral, the same type of galaxy as the Milky Way, but unlike our home in space it has a ‘double nucleus’ at its heart.
Engaging rings
CASSINI SpACECrAfT 20 JANuAry 2014
Saturn’s famous ring system takes centre stage in this infrared image from Cassini. Taken from a distance of 1.1 million km, it reveals a bright spot in the rings – look for it just left of centre – called an opposition surge. This occurs when the Sun is directly behind the probe. Astronomers will analyse the size and magnitude of the surge to learn more about the properties of the ring particles.
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skyatnightmagazine.com 2014
Rose tinted gasses
EurOpEAN SOuTHErN ObSErvATOry, 22 JANuAry 2014
ESO’s very large Telescope captured the lagoon Nebula in exquisite, pale pink detail in this stunning new image. The nebula, a vast stellar factory where new stars are born, spans almost 100 lightyears in diameter, and lies between 4,000 and 6,000 lightyears from Earth.
The leftover lake
MArS ExprESS SpACECrAfT, 12 dECEMbEr 2013
Giant mounds of layered deposits sit surrounded by soft sand and dust in Mars’s Juventae Chasma. New observations like the one from ESA’s Mars Express indicate that running water may have been responsible for moulding these mounds – scientists believe the numerous layers were mainly built up from lake deposits.
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eye on the sky APRIL 09
skyatnightmagazine.com 2014
Rose tinted gasses
EurOpEAN SOuTHErN ObSErvATOry, 22 JANuAry 2014
ESO’s very large Telescope captured the lagoon Nebula in exquisite, pale pink detail in this stunning new image. The nebula, a vast stellar factory where new stars are born, spans almost 100 lightyears in diameter, and lies between 4,000 and 6,000 lightyears from Earth.
The leftover lake
MArS ExprESS SpACECrAfT, 12 dECEMbEr 2013
Giant mounds of layered deposits sit surrounded by soft sand and dust in Mars’s Juventae Chasma. New observations like the one from ESA’s Mars Express indicate that running water may have been responsible for moulding these mounds – scientists believe the numerous layers were mainly built up from lake deposits.
THE ASPEN SERIES IS OUR NEWEST AND
MOST ADVANCED CCD CAMERA EVER.
Image of Ghost Nebula (vdB 141) shot using our new Aspen CG16m CCD camera
©2013 Apogee Imaging Systems Inc. Aspen is a trademark of Apogee Imaging Systems, Inc.
Aspen delivers industry-leading performance with both its cooling (up to -70 degrees C) and its shutter with
reliability rated at 5 million cycles. All this is achieved within a smaller form factor. Aspen also delivers improved
stray light baffling to minimize internal reflections and its back-focus requirements have been reduced to
accommodate more OTAs and accessories. Aspen Series cameras come standard with 2 interfaces, USB 2
and an Ethernet interface with a built-in web server. Read out rates up to 16Mhz are supported. All our cameras
are backed by a full 2-year warranty on the camera and lifetime warranty on the CCD chamber integrity.
Our new Aspen Series delivers quality and reliability so you can focus on innovation and discovery.
THE ASPEN SERIES IS OUR NEWEST AND
MOST ADVANCED CCD CAMERA EVER.
Image of Ghost Nebula (vdB 141) shot using our new Aspen CG16m CCD camera
©2013 Apogee Imaging Systems Inc. Aspen is a trademark of Apogee Imaging Systems, Inc.
Aspen delivers industry-leading performance with both its cooling (up to -70 degrees C) and its shutter with
reliability rated at 5 million cycles. All this is achieved within a smaller form factor. Aspen also delivers improved
stray light baffling to minimize internal reflections and its back-focus requirements have been reduced to
accommodate more OTAs and accessories. Aspen Series cameras come standard with 2 interfaces, USB 2
and an Ethernet interface with a built-in web server. Read out rates up to 16Mhz are supported. All our cameras
are backed by a full 2-year warranty on the camera and lifetime warranty on the CCD chamber integrity.
Our new Aspen Series delivers quality and reliability so you can focus on innovation and discovery.
Comment by Chris LintottThe key to understanding this bizarre new system is that it orbits not one, but two stars – one of a handful of ‘circumbinary’ planets known.
Since the discovery of the frst such world, a hardy group of theorists and computer modellers have been trying to fgure out the rules that dictate how such planets might form. Their results suggested that the gravitational pull of the binary star would wrench any protoplanetary disc and hence any subsequent planets into alignment.
That process clearly wasn’t effective here, leaving Kepler-413b on an orbit that only sometimes produces transits. Its inclination is only a couple of degrees – not unprecedented, but enough in this case to make a big difference to what we see. With planets around binary stars already proving much more common than anyone would have suspected a few years ago, this window onto what we might be missing is hugely signifcant.
ChrIS LInToTT co-presents The Sky at Night
The latest astronomy and space news written by Hazel Muir
Our experts examine the hottest new astronomy research papers
CUttInG
eDGe
plUs
Circumbinary planets are rare, with only a handful found so far
Bulletin APRIL 11
skyatnightmagazine.com 2014
Bulletin
NA
SA
/JPL
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14 CHris LintOtt 16 Lewis DartneLL
Wobbly planet circles
double starNASA ScieNtiStS hAve discovered a strange
world that wobbles wildly on its axis, much like
a child’s spinning top. its tilt may change by as
much as 30º over 11 years, resulting in extreme
and rapid climate changes.
the planet, a gas giant known as Kepler-413b,
is about 65 times as massive as earth and sits in
the constellation of cygnus. it orbits a close pair
of dwarf stars every 66 days, causing them to
dim slightly as it passes in front. this should
happen like clockwork but – as the Kepler space
telescope revealed – the gas giant’s transits are
unusually irregular.
“Looking at the Kepler data over the course of
1,500 days, we saw three transits in the first 180
days, then we had 800 days with no transits at all,”
says team leader veselin Kostov from the Space
telescope Science institute (StSci) in Maryland.
“After that, we saw five more transits in a row.”
the planet’s orbit is tilted by 2.5º in relation
to the orbit of the binary stellar pair; these
observations suggest that the planet’s orbit
wobbles too, so much that the planet often
fails to pass in front of the stars from our
perspective on earth.
intriguingly, the finding may also mean that
many transiting planets may go undetected
because their transits are rare. “Presumably
there are planets out there like this one that
we’re not seeing because we’re in the
unfavourable period,” says Peter Mccullough,
also from StSci. “is there a silent majority
that we’re not seeing?”
> See Comment, right
Is this the frst member of a ‘silent majority’ of unseen planets?
Comment by Chris LintottThe key to understanding this bizarre new system is that it orbits not one, but two stars – one of a handful of ‘circumbinary’ planets known.
Since the discovery of the frst such world, a hardy group of theorists and computer modellers have been trying to fgure out the rules that dictate how such planets might form. Their results suggested that the gravitational pull of the binary star would wrench any protoplanetary disc and hence any subsequent planets into alignment.
That process clearly wasn’t effective here, leaving Kepler-413b on an orbit that only sometimes produces transits. Its inclination is only a couple of degrees – not unprecedented, but enough in this case to make a big difference to what we see. With planets around binary stars already proving much more common than anyone would have suspected a few years ago, this window onto what we might be missing is hugely signifcant.
ChrIS LInToTT co-presents The Sky at Night
The latest astronomy and space news written by Hazel Muir
Our experts examine the hottest new astronomy research papers
CUttInG
eDGe
plUs
Circumbinary planets are rare, with only a handful found so far
Bulletin APRIL 11
skyatnightmagazine.com 2014
Bulletin N
ASA
/JPL
-CA
LteC
h
14 CHris LintOtt 16 Lewis DartneLL
Wobbly planet circles
double starNASA ScieNtiStS hAve discovered a strange
world that wobbles wildly on its axis, much like
a child’s spinning top. its tilt may change by as
much as 30º over 11 years, resulting in extreme
and rapid climate changes.
the planet, a gas giant known as Kepler-413b,
is about 65 times as massive as earth and sits in
the constellation of cygnus. it orbits a close pair
of dwarf stars every 66 days, causing them to
dim slightly as it passes in front. this should
happen like clockwork but – as the Kepler space
telescope revealed – the gas giant’s transits are
unusually irregular.
“Looking at the Kepler data over the course of
1,500 days, we saw three transits in the first 180
days, then we had 800 days with no transits at all,”
says team leader veselin Kostov from the Space
telescope Science institute (StSci) in Maryland.
“After that, we saw five more transits in a row.”
the planet’s orbit is tilted by 2.5º in relation
to the orbit of the binary stellar pair; these
observations suggest that the planet’s orbit
wobbles too, so much that the planet often
fails to pass in front of the stars from our
perspective on earth.
intriguingly, the finding may also mean that
many transiting planets may go undetected
because their transits are rare. “Presumably
there are planets out there like this one that
we’re not seeing because we’re in the
unfavourable period,” says Peter Mccullough,
also from StSci. “is there a silent majority
that we’re not seeing?”
> See Comment, right
Is this the frst member of a ‘silent majority’ of unseen planets?
12
skyatnightmagazine.com 2014
Newly discovered gas streams may explain vigorous star formation
An intriguing river of hydrogen fowing
through space has been spotted by a radio
telescope in West virginia. Astronomers say
such flaments, never seen before because they
are so faint, could explain how some spiral
galaxies manage to maintain constant, vigorous
star formation.
Spiral galaxies like our own Milky Way
typically have rather tranquil, but steady,
star formation. But the star formation in some
others is more lively. these galaxies often
have warm shrouds of hydrogen gas, but
astronomers suspected they must also have
cold hydrogen infows to explain the high
star-formation rates.
“We knew that the fuel for star formation had
to come from somewhere,” says Daniel Pisano
from West virginia university in Morgantown.
“So far, however, we’ve detected only about 10
per cent of what would be necessary to explain
what we observe in many galaxies.”
One leading theory is that rivers of gas,
known as cold fows, ferry hydrogen through
intergalactic space, with large galaxies
Odyssey gets a new quest NASA is gradually altering the orbit of its Mars Odyssey spacecraft to allow the probe to view the planet’s surface in morning daylight. It will reach its intended new orbit in November 2015 and make the frst systematic observations of how morning fogs, clouds and surface frost develop.
Its measurements could help demystify temperature- driven processes, such as fows forming on slopes during warm seasons.
“We’re teaching an old spacecraft new tricks,” says Jeffrey Plaut from NASA’s Jet Propulsion Laboratory in California. “Odyssey will be in position to see Mars in a different light than ever before.”
effectively siphoning cold gas away from
their smaller neighbours. the cold gas then
becomes fuel for new stars. “But this tenuous
hydrogen has been simply too diffuse to
detect, until now,” says Pisano.
He has discovered one of the hypothesised
rivers of hydrogen after studying a galaxy called
ngC 6946. this galaxy lies about 22 million
lightyears away on the border of the Cepheus
and Cygnus. Observations using the 100m green
Bank telescope revealed the faint glow of a
neutral hydrogen stream connecting ngC 6946
with neighbouring galaxies, suggesting it does
indeed siphon hydrogen off its smaller neighbours.
An alternative possibility is that the cold
hydrogen stream exists because ngC 6946 had
a close encounter with another galaxy in the
distant past. this interaction could have left a
ribbon of neutral atomic hydrogen in its wake.
if that were the case, however, astronomers
would expect to see a small but observable
population of stars in the flament, which
have not been detected.
www.gb.nrao.edu
NA
SA
/JPL
, D
.J. Pi
SA
No
(W
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) B.
SA
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NR
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news in
brief
Rivers of hydrogen fuel galaxies
ngC 6946 and its companions appear to be linked by a trail of diffuse hydrogen, shown in red
extreme blaCk hOle disCOveredA black hole in an elliptical galaxy about 3.9 billion lightyears away may be the most powerful ever found.
Julie Hlavacek-Larrondo from Stanford University in California and colleagues made the discovery using NASA’s Chandra X-ray Observatory and other telescopes. They estimate that the black hole is about a thousand trillion times as massive as the Sun. Energetic jets sprouting out from it seem to have created two large cavities, each as wide as our Milky Way, severely curtailing star formation.
12
skyatnightmagazine.com 2014
Newly discovered gas streams may explain vigorous star formation
An intriguing river of hydrogen fowing
through space has been spotted by a radio
telescope in West virginia. Astronomers say
such flaments, never seen before because they
are so faint, could explain how some spiral
galaxies manage to maintain constant, vigorous
star formation.
Spiral galaxies like our own Milky Way
typically have rather tranquil, but steady,
star formation. But the star formation in some
others is more lively. these galaxies often
have warm shrouds of hydrogen gas, but
astronomers suspected they must also have
cold hydrogen infows to explain the high
star-formation rates.
“We knew that the fuel for star formation had
to come from somewhere,” says Daniel Pisano
from West virginia university in Morgantown.
“So far, however, we’ve detected only about 10
per cent of what would be necessary to explain
what we observe in many galaxies.”
One leading theory is that rivers of gas,
known as cold fows, ferry hydrogen through
intergalactic space, with large galaxies
Odyssey gets a new quest NASA is gradually altering the orbit of its Mars Odyssey spacecraft to allow the probe to view the planet’s surface in morning daylight. It will reach its intended new orbit in November 2015 and make the frst systematic observations of how morning fogs, clouds and surface frost develop.
Its measurements could help demystify temperature- driven processes, such as fows forming on slopes during warm seasons.
“We’re teaching an old spacecraft new tricks,” says Jeffrey Plaut from NASA’s Jet Propulsion Laboratory in California. “Odyssey will be in position to see Mars in a different light than ever before.”
effectively siphoning cold gas away from
their smaller neighbours. the cold gas then
becomes fuel for new stars. “But this tenuous
hydrogen has been simply too diffuse to
detect, until now,” says Pisano.
He has discovered one of the hypothesised
rivers of hydrogen after studying a galaxy called
ngC 6946. this galaxy lies about 22 million
lightyears away on the border of the Cepheus
and Cygnus. Observations using the 100m green
Bank telescope revealed the faint glow of a
neutral hydrogen stream connecting ngC 6946
with neighbouring galaxies, suggesting it does
indeed siphon hydrogen off its smaller neighbours.
An alternative possibility is that the cold
hydrogen stream exists because ngC 6946 had
a close encounter with another galaxy in the
distant past. this interaction could have left a
ribbon of neutral atomic hydrogen in its wake.
if that were the case, however, astronomers
would expect to see a small but observable
population of stars in the flament, which
have not been detected.
www.gb.nrao.edu
NA
SA
/JPL
, D
.J.
PiSA
No
(W
VU
) B.
SA
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NR
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SF)
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SA
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-cA
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AN
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SA
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h/U
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F A
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A/L
AN
cA
Ste
R U
NiV
eRSit
y
news in
brief
Rivers of hydrogen fuel galaxies
ngC 6946 and its companions appear to be linked by a trail of diffuse hydrogen, shown in red
extreme blaCk hOle disCOveredA black hole in an elliptical galaxy about 3.9 billion lightyears away may be the most powerful ever found.
Julie Hlavacek-Larrondo from Stanford University in California and colleagues made the discovery using NASA’s Chandra X-ray Observatory and other telescopes. They estimate that the black hole is about a thousand trillion times as massive as the Sun. Energetic jets sprouting out from it seem to have created two large cavities, each as wide as our Milky Way, severely curtailing star formation.
Bulletin APRIL 13
skyatnightmagazine.com 2014
gALACTIC fAMILy TrEES NO LONgEr A MySTEryRigoRous obseRvations by world-leading
telescopes, including Hubble and Herschel, have
unravelled the history of the most massive galaxies
in the universe. the results show how early galaxies
evolved via initial violent bursts of star formation
into extremely high-density galaxy cores, then
fnally collided to form giant elliptical galaxies.
the timeline solves a decade-long mystery
about how compact elliptical galaxies that existed
when the universe was only three billion years old
– less than a quarter of its current age – but had
already completed most of their star formation.
Asteroid’s odd interior revealed
asteRoids can Have a highly varied internal
structure, scientists say. observations of peanut-
shaped near-earth asteroid 25143 itokawa suggest
that its density is more than 60 per cent higher on
one side than it is on the other. it’s the frst time
that such a difference has been found.
stephen Lowry from the university of Kent
and colleagues studied the space rock – visited by
the Japanese spacecraft Hayabusa in 2005 – using
a telescope at the La silla observatory in chile.
their measurements of its spin rate combined
with theoretical models hint that itokawa has two
distinct densities. one possibility for this could
be that it formed from two rocks that merged.
“this is the frst time we have ever been able to
determine what it is like inside an asteroid,” says
Lowry, who calls it “a signifcant step” forward.
www.eso.org/lasilla
nasa and FranCe plan mars prObeThe US has teamed up with france to launch a lander to Mars in 2016. Space offcials from both nations have signed an agreement to join forces on the InSight mission, which will measure seismic activity on Mars and reveal structural details of its deep interior.
“The research generated by this collaborative mission will give our agencies more information about the early formation of Mars, which will help us understand more about how Earth evolved,” says NASA administrator Charles Bolden.
saturn’s aurOrae in Full glOryUsing images from Hubble and NASA’s Cassini spacecraft from April and May 2013, astronomers have compiled a movie of aurorae at Saturn’s poles. It should clarify how the giant planet’s polar light shows evolve following solar outbursts.
“In 2013, we were treated to a veritable smorgasbord of dancing aurorae, from steadily shining rings to super-fast bursts of light shooting across the pole,” says Jonathan Nichols from the University of Leicester, who led the work on the Hubble images.
news in
brief The density of a space rock can be extremely variable
the two parts of asteroid itokawa have markedly different densities
the study directly shows they’re descendants of
an earlier population of dusty ‘starburst’ galaxies
that voraciously used up available gas for star
formation very quickly.
“We at last show how these compact galaxies can
form, how it happened and when it happened,” says
sune toft from the niels bohr institute in copenhagen,
denmark, whose team confrmed the evolutionary
tree through detailed studies of many galaxies of
different ages. after the compact phase, the galaxies
grew slowly through mergers into giant ellipticals.
www.hubblesite.org
2,850kg/m3
1,750kg/m3
the evolution of giant ellipticals has been laid bare
tOday
13.7 billion years 5 billion years3 billion years
2 billion years1.5 billion years
1 billion years
local elliptical galaxymerging galaxies
Compact galaxy
quasardusty starburst
galaxy
merger
big bang
Bulletin APRIL 13
skyatnightmagazine.com 2014
gALACTIC fAMILy TrEES NO LONgEr A MySTEryRigoRous obseRvations by world-leading
telescopes, including Hubble and Herschel, have
unravelled the history of the most massive galaxies
in the universe. the results show how early galaxies
evolved via initial violent bursts of star formation
into extremely high-density galaxy cores, then
fnally collided to form giant elliptical galaxies.
the timeline solves a decade-long mystery
about how compact elliptical galaxies that existed
when the universe was only three billion years old
– less than a quarter of its current age – but had
already completed most of their star formation.
Asteroid’s odd interior revealed
asteRoids can Have a highly varied internal
structure, scientists say. observations of peanut-
shaped near-earth asteroid 25143 itokawa suggest
that its density is more than 60 per cent higher on
one side than it is on the other. it’s the frst time
that such a difference has been found.
stephen Lowry from the university of Kent
and colleagues studied the space rock – visited by
the Japanese spacecraft Hayabusa in 2005 – using
a telescope at the La silla observatory in chile.
their measurements of its spin rate combined
with theoretical models hint that itokawa has two
distinct densities. one possibility for this could
be that it formed from two rocks that merged.
“this is the frst time we have ever been able to
determine what it is like inside an asteroid,” says
Lowry, who calls it “a signifcant step” forward.
www.eso.org/lasilla
nasa and FranCe plan mars prObeThe US has teamed up with france to launch a lander to Mars in 2016. Space offcials from both nations have signed an agreement to join forces on the InSight mission, which will measure seismic activity on Mars and reveal structural details of its deep interior.
“The research generated by this collaborative mission will give our agencies more information about the early formation of Mars, which will help us understand more about how Earth evolved,” says NASA administrator Charles Bolden.
saturn’s aurOrae in Full glOryUsing images from Hubble and NASA’s Cassini spacecraft from April and May 2013, astronomers have compiled a movie of aurorae at Saturn’s poles. It should clarify how the giant planet’s polar light shows evolve following solar outbursts.
“In 2013, we were treated to a veritable smorgasbord of dancing aurorae, from steadily shining rings to super-fast bursts of light shooting across the pole,” says Jonathan Nichols from the University of Leicester, who led the work on the Hubble images.
news in
brief The density of a space rock can be extremely variable
the two parts of asteroid itokawa have markedly different densities
the study directly shows they’re descendants of
an earlier population of dusty ‘starburst’ galaxies
that voraciously used up available gas for star
formation very quickly.
“We at last show how these compact galaxies can
form, how it happened and when it happened,” says
sune toft from the niels bohr institute in copenhagen,
denmark, whose team confrmed the evolutionary
tree through detailed studies of many galaxies of
different ages. after the compact phase, the galaxies
grew slowly through mergers into giant ellipticals.
www.hubblesite.org
2,850kg/m3
1,750kg/m3
the evolution of giant ellipticals has been laid bare
tOday
13.7 billion years 5 billion years3 billion years
2 billion years1.5 billion years
1 billion years
local elliptical galaxymerging galaxies
Compact galaxy
quasardusty starburst
galaxy
merger
big bang
NA
SA/E
SA, A
. G
oo
bAr
(Sto
ck
ho
lm U
Niv
ErSi
ty)
AN
d t
hE
hU
bblE
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itA
GE
tEA
m (
StSc
i/A
Ur
A)
skyatnightmagazine.com 2014
14
Most of the buzz surrounding the recent
supernova 2014J in relatively local
M82 is due to its status as the nearest
Type Ia event in more than a century.
We normally hear about Type Ia supernovae when
they’re used to measure the expansion of the
Universe and the effects of ‘dark energy’, but all of
this cosmological excitement hides the embarrassing
truth that these supernovae are poorly understood.
The standard picture of a Type Ia supernova
depends on the transfer of material between two
stars, locked in a mutual gravitational embrace in a
binary system. If one of the stars is a white dwarf,
and the two are close enough, then material will be
pulled off the larger star and build up on the
smaller one. Once enough material has accreted,
then thermonuclear ignition becomes inevitable,
and we see a supernova.
This seems right – the need for a set amount of
material to trigger ignition explains why Type Ia
supernovae have roughly the same luminosity
wherever they occur, with some adjustment for
factors such as the composition of the material. But
not all Type Ia supernovae ft this pattern. Suggestions
include exotic models of stellar evolution, interactions
between two white dwarfs or even mergers in triple
star systems. Whatever is going on, a growing body
of evidence suggests an important role is played by
so-called ‘prompt’ Type Ia supernovae, which occur
less than 500 million years into a system’s lifetime.
A new Hubble Space Telescope survey of 24 Type
Ia supernovae sets out to understand how the
distribution of prompt and standard supernovae
has changed over cosmic time. Given that this
survey looks more than 10 billion years into the
past, to a time when star formation was much more
prevalent than it is today, we should expect the
number of progenitors capable of producing either
prompt or standard supernovae to be different from
that in the local Universe. Previous surveys had
suggested that such analysis would reveal that the
prompt variant might account for as many as half
of all Type Ia supernovae. Given the rising star-
formation rate as we look back in time, that should
mean plenty of supernovae for us to observe.
In fact, few supernovae were found in the most
distant galaxies included in the survey, which
suggests that prompt supernovae accounting for
half of all such events might be an overestimation.
The data favour a much lower fraction, perhaps as
small as one in 20, albeit with small error bars.
Far from understanding what prompt Type Ia
supernovae are, we’re still struggling to count them.
More observations will help, and large Hubble surveys
are already underway. Given M82’s status as a
prolifc star-forming system, though, and the
chance that 2014J is a prompt event, perhaps the
best way to study these objects is to look closer to
home, fun though staring at the distant Universe is.
Chris Lintott is an astrophysicist and co-presenter of The Sky at Night on BBC TV. He is also the director of the Zooniverse project.
Chris Lintott was reading… Type Ia Supernova Rate Measurements to Redshift 2.5 from CANDELS: Searching for Prompt Explosions in the Early Universe by Steven A Rodney et alread it online at http://arxiv.org/abs/1401.7978
our experts examine the hottest new research
the type ia supernova designated 2014J exploded in M82, 11.5 million lightyears from Earth. it was the closest supernova of this type discovered in the past few decades
The prompt supernovaeType Ia supernovae appear to be more varied then we originally thought
CUTTING
EDGE
“A growing body of evidence suggests an important role is played by prompt Type Ia supernovae”
NA
SA/E
SA,
A.
Go
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r (S
toc
kh
olm
UN
ivEr
Sity
) A
Nd
th
E h
Ubb
lE h
Erit
AG
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Am
(St
Sci/
AU
rA
)
skyatnightmagazine.com 2014
14
Most of the buzz surrounding the recent
supernova 2014J in relatively local
M82 is due to its status as the nearest
Type Ia event in more than a century.
We normally hear about Type Ia supernovae when
they’re used to measure the expansion of the
Universe and the effects of ‘dark energy’, but all of
this cosmological excitement hides the embarrassing
truth that these supernovae are poorly understood.
The standard picture of a Type Ia supernova
depends on the transfer of material between two
stars, locked in a mutual gravitational embrace in a
binary system. If one of the stars is a white dwarf,
and the two are close enough, then material will be
pulled off the larger star and build up on the
smaller one. Once enough material has accreted,
then thermonuclear ignition becomes inevitable,
and we see a supernova.
This seems right – the need for a set amount of
material to trigger ignition explains why Type Ia
supernovae have roughly the same luminosity
wherever they occur, with some adjustment for
factors such as the composition of the material. But
not all Type Ia supernovae ft this pattern. Suggestions
include exotic models of stellar evolution, interactions
between two white dwarfs or even mergers in triple
star systems. Whatever is going on, a growing body
of evidence suggests an important role is played by
so-called ‘prompt’ Type Ia supernovae, which occur
less than 500 million years into a system’s lifetime.
A new Hubble Space Telescope survey of 24 Type
Ia supernovae sets out to understand how the
distribution of prompt and standard supernovae
has changed over cosmic time. Given that this
survey looks more than 10 billion years into the
past, to a time when star formation was much more
prevalent than it is today, we should expect the
number of progenitors capable of producing either
prompt or standard supernovae to be different from
that in the local Universe. Previous surveys had
suggested that such analysis would reveal that the
prompt variant might account for as many as half
of all Type Ia supernovae. Given the rising star-
formation rate as we look back in time, that should
mean plenty of supernovae for us to observe.
In fact, few supernovae were found in the most
distant galaxies included in the survey, which
suggests that prompt supernovae accounting for
half of all such events might be an overestimation.
The data favour a much lower fraction, perhaps as
small as one in 20, albeit with small error bars.
Far from understanding what prompt Type Ia
supernovae are, we’re still struggling to count them.
More observations will help, and large Hubble surveys
are already underway. Given M82’s status as a
prolifc star-forming system, though, and the
chance that 2014J is a prompt event, perhaps the
best way to study these objects is to look closer to
home, fun though staring at the distant Universe is.
Chris Lintott is an astrophysicist and co-presenter of The Sky at Night on BBC TV. He is also the director of the Zooniverse project.
Chris Lintott was reading… Type Ia Supernova Rate Measurements to Redshift 2.5 from CANDELS: Searching for Prompt Explosions in the Early Universe by Steven A Rodney et alread it online at http://arxiv.org/abs/1401.7978
our experts examine the hottest new research
the type ia supernova designated 2014J exploded in M82, 11.5 million lightyears from Earth. it was the closest supernova of this type discovered in the past few decades
The prompt supernovaeType Ia supernovae appear to be more varied then we originally thought
CUTTING
EDGE
“A growing body of evidence suggests an important role is played by prompt Type Ia supernovae”
As pulsars spin, their
radiation beams sweep
across the cosmos
skyatnightmagazine.com 2014
April 1983On 10 April 1983, The Sky at Night broadcast discussed a bizarre new sighting in the night sky. Astronomers had discovered a pulsar, known as PSR B1937+21, spinning 642 times a second.
A pulsar is a neutron star, which forms when a massive star explodes in a supernova, leaving behind a superdense core roughly 15km wide. Neutron stars can emit intense radiation from their magnetic poles, and if their radiation beams sweep
Mars gains a fresh crater
GAiA OPeNS itS eyeS
Spacecraft images reveal a spectacular new impact
ESA’S GAiA SpAcEcrAft has taken a stunning
test image following its launch in December 2013.
the shot, shown right, shows a dense cluster of
stars within the Large Magellanic cloud, a
satellite galaxy of the Milky Way.
“it provides just a tiny taste of the excellence
and challenges ahead, to turn Gaia data into
human understanding of the Milky Way’s
origins,” says Gaia scientist Gerry Gilmore from
the University of cambridge. “One substantial
step for astronomy, one huge leap still to come.”
Gaia will observe a billion stars around
70 times every year in an attempt to build our
most accurate map of the Milky Way.
http://sci.esa.int/gaia
NASA’S MArS rEcONNAiSSANcE Orbiter has
spotted a dramatic new crater on the red planet.
the impact scar, which is around 30km wide,
did not exist in images dating back to July 2010,
but turned up in shots taken in May 2012. After
noticing the change, scientists used the orbiter’s
HiriSE camera to take a closer look at the
region in November 2013 – capturing the image
shown on the left.
it’s been estimated that more than 200 of the
space rocks that hit Mars every year create craters at
least 3.9m wide, but few of the impacts look as striking
as this one, which is surrounded a radial burst of
debris that few out over a distance of about 15km.
NASA launched the Mars reconnaissance Orbiter
in August 2005. it entered Mars’s orbit in March 2006.
www.nasa.gov/mroThe new crater is not really blue; this tint is a result of enhanced colourisation to remove reddish dust
Looking back
Bulletin APRIL 15
NA
SA
/JPL
-CA
LteC
h/U
Niv
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f A
riz
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A, eS
A/D
PAC
/Air
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We’re unlikely to see many images like this from Gaia – its main role is that of a galactic cartographer
across earth as they rotate, we can observe regular pulses from them.
the discovery of PSR B1937+21 was extraordinary – how could a pulsar possibly spin that fast? Astronomers concluded that they can be spun up to enormous speeds when companion stars dump material onto them, delivering angular momentum. the spin rate of PSR B1937+21 has since been surpassed by only one other known pulsar, spinning 716 times a second.
BroWn dWArf hAs red skiesUsing the Very Large telescope in Chile, astronomers have found a nearby brown dwarf star with curiously red skies.
Brown dwarfs are stars that are too small to ignite hydrogen fusion in their cores but too large to be considered planets. One brown dwarf that lies at least 100 lightyears away caught the attention of Federico Marocco from the University of Hertfordshire and his colleagues due to its unusually red atmosphere.
“the thick clouds on this particular brown dwarf are mostly made of mineral dust,” says Marocco. the compounds include the magnesium-rich mineral enstatite and a crystalline form of aluminium oxide.
news in
brief
Mercury iMAGes MounT upNASA’s Messenger spacecraft, launched in 2004, has now returned more than 200,000 images of the planet Mercury – 200 times the number promised in the mission proposal. the probe will now have its orbit lowered so it can take high-resolution images of the rocky world’s surface.
As pulsars spin, their
radiation beams sweep
across the cosmos
skyatnightmagazine.com 2014
April 1983On 10 April 1983, The Sky at Night broadcast discussed a bizarre new sighting in the night sky. Astronomers had discovered a pulsar, known as PSR B1937+21, spinning 642 times a second.
A pulsar is a neutron star, which forms when a massive star explodes in a supernova, leaving behind a superdense core roughly 15km wide. Neutron stars can emit intense radiation from their magnetic poles, and if their radiation beams sweep
Mars gains a fresh crater
GAiA OPeNS itS eyeS
Spacecraft images reveal a spectacular new impact
ESA’S GAiA SpAcEcrAft has taken a stunning
test image following its launch in December 2013.
the shot, shown right, shows a dense cluster of
stars within the Large Magellanic cloud, a
satellite galaxy of the Milky Way.
“it provides just a tiny taste of the excellence
and challenges ahead, to turn Gaia data into
human understanding of the Milky Way’s
origins,” says Gaia scientist Gerry Gilmore from
the University of cambridge. “One substantial
step for astronomy, one huge leap still to come.”
Gaia will observe a billion stars around
70 times every year in an attempt to build our
most accurate map of the Milky Way.
http://sci.esa.int/gaia
NASA’S MArS rEcONNAiSSANcE Orbiter has
spotted a dramatic new crater on the red planet.
the impact scar, which is around 30km wide,
did not exist in images dating back to July 2010,
but turned up in shots taken in May 2012. After
noticing the change, scientists used the orbiter’s
HiriSE camera to take a closer look at the
region in November 2013 – capturing the image
shown on the left.
it’s been estimated that more than 200 of the
space rocks that hit Mars every year create craters at
least 3.9m wide, but few of the impacts look as striking
as this one, which is surrounded a radial burst of
debris that few out over a distance of about 15km.
NASA launched the Mars reconnaissance Orbiter
in August 2005. it entered Mars’s orbit in March 2006.
www.nasa.gov/mroThe new crater is not really blue; this tint is a result of enhanced colourisation to remove reddish dust
Looking back
Bulletin APRIL 15
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We’re unlikely to see many images like this from Gaia – its main role is that of a galactic cartographer
across earth as they rotate, we can observe regular pulses from them.
the discovery of PSR B1937+21 was extraordinary – how could a pulsar possibly spin that fast? Astronomers concluded that they can be spun up to enormous speeds when companion stars dump material onto them, delivering angular momentum. the spin rate of PSR B1937+21 has since been surpassed by only one other known pulsar, spinning 716 times a second.
BroWn dWArf hAs red skiesUsing the Very Large telescope in Chile, astronomers have found a nearby brown dwarf star with curiously red skies.
Brown dwarfs are stars that are too small to ignite hydrogen fusion in their cores but too large to be considered planets. One brown dwarf that lies at least 100 lightyears away caught the attention of Federico Marocco from the University of Hertfordshire and his colleagues due to its unusually red atmosphere.
“the thick clouds on this particular brown dwarf are mostly made of mineral dust,” says Marocco. the compounds include the magnesium-rich mineral enstatite and a crystalline form of aluminium oxide.
news in
brief
Mercury iMAGes MounT upNASA’s Messenger spacecraft, launched in 2004, has now returned more than 200,000 images of the planet Mercury – 200 times the number promised in the mission proposal. the probe will now have its orbit lowered so it can take high-resolution images of the rocky world’s surface.
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skyatnightmagazine.com 2014
16
Io is the most volcanically active body in
the Solar System. It’s a fractious and violent
little world, and fascinating to study as its
face is constantly changing. We learned a
lot about Io from the Galileo probe’s tour of the
Jovian system between 1996 and 2001, and got
a feeting glimpse most recently when the New
Horizons probe swung past Jupiter on its journey
towards Pluto.
For a few days around 28 February 2007, New
Horizons was able to train its cameras on Io. It took
200 photos of Jupiter’s moon during this fyby and
Dr Julie Rathbun of the Planetary Science Institute
in Tuscon and colleagues have written a paper
about what they show. Many of the photos were
taken when Jupiter was eclipsing Io, casting a
shadow over the moon’s surface – perfect for
hunting for glowing volcanic areas.
Most of the volcanoes observed by the Galileo
probe were still active when New Horizons few
past, six years later. One of them, Pele, is among
Io’s most enduring hotspots – it was glowing when
it was frst detected by Voyager in 1979 and Rathbun
found that it was still going strong in 2007. New
Horizons was able to photograph several volcanoes
repeatedly and found no variability in their
brightness – they’re very stable in their intensity.
By far the brightest hotspot seen by New
Horizons was a volcano called Tvashtar. It was such
an intense thermal source that it didn’t just show up
in images taken using an infrared flter, but also those
taken in the red band. This was important because it
allowed Rathbun to work out Tvashtar’s temperature.
The hotter an object is, the shorter the
wavelength of light it emits. The human body glows
in the far-infrared at about 10μm; a red-hot poker
emits light at wavelengths a few microns long; light
emitted by the Sun peaks at about 0.5μm, shining
brilliantly at visible and ultraviolet wavelengths. By
comparing the brightness of Tvashtar at both
infrared and red wavelengths, Rathbun was able to
calculate the hotspot’s temperature to be about
950°C, which is the same as lava fows on Earth.
Curiously, East Girru, the second-brightest
thermal source seen on Io by New Horizons wasn’t
seen by Voyager in 1979, or Galileo in the late 1990s,
or indeed from any ground-based telescopes. East
Girru lies 200km from a hotspot that was seen by
Galileo, and so Rathbun has concluded that it’s a
new eruption. But, when comparing the highest-
resolution photos from Galileo and New Horizons
of the landscape around East Girru, she couldn’t
see any noticeable changes between the two, nor
any lighter region of the type that’s normally seen
around volcanic sites on Io. So this new intense
hotspot is something of a mystery: what’s the
source of all that activity?
Lewis DartneLL is an astrobiology research fellow at the University of Leicester. His new book The Knowledge will be published in April.
Lewis DartneLL was reading… Io’s active volcanoes during the New Horizons era: Insights from New Horizons imaging by J A rathbun et al. read it online at http://dx.doi.org/10.1016/ j.icarus.2013.12.002
Our experts examine the hottest new research
io seen through three new Horizons instruments; the tvashtar volcano near the moon’s north pole is the brightest hotspot in each image, with a temperature of 950°C
The violence of IoImages taken by the New Horizons probe are giving us a greater insight into this highly volcanic moon
CUTTING
EDGE
“Pele was glowing when it was frst detected by Voyager in 1979 and was still going strong in 2007”
NA
SA/J
oh
NS
ho
pkiN
S U
Niv
erSi
ty A
ppli
ed p
hyS
icS
lAbo
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/So
Uth
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t re
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iNSt
itU
te
skyatnightmagazine.com 2014
16
Io is the most volcanically active body in
the Solar System. It’s a fractious and violent
little world, and fascinating to study as its
face is constantly changing. We learned a
lot about Io from the Galileo probe’s tour of the
Jovian system between 1996 and 2001, and got
a feeting glimpse most recently when the New
Horizons probe swung past Jupiter on its journey
towards Pluto.
For a few days around 28 February 2007, New
Horizons was able to train its cameras on Io. It took
200 photos of Jupiter’s moon during this fyby and
Dr Julie Rathbun of the Planetary Science Institute
in Tuscon and colleagues have written a paper
about what they show. Many of the photos were
taken when Jupiter was eclipsing Io, casting a
shadow over the moon’s surface – perfect for
hunting for glowing volcanic areas.
Most of the volcanoes observed by the Galileo
probe were still active when New Horizons few
past, six years later. One of them, Pele, is among
Io’s most enduring hotspots – it was glowing when
it was frst detected by Voyager in 1979 and Rathbun
found that it was still going strong in 2007. New
Horizons was able to photograph several volcanoes
repeatedly and found no variability in their
brightness – they’re very stable in their intensity.
By far the brightest hotspot seen by New
Horizons was a volcano called Tvashtar. It was such
an intense thermal source that it didn’t just show up
in images taken using an infrared flter, but also those
taken in the red band. This was important because it
allowed Rathbun to work out Tvashtar’s temperature.
The hotter an object is, the shorter the
wavelength of light it emits. The human body glows
in the far-infrared at about 10μm; a red-hot poker
emits light at wavelengths a few microns long; light
emitted by the Sun peaks at about 0.5μm, shining
brilliantly at visible and ultraviolet wavelengths. By
comparing the brightness of Tvashtar at both
infrared and red wavelengths, Rathbun was able to
calculate the hotspot’s temperature to be about
950°C, which is the same as lava fows on Earth.
Curiously, East Girru, the second-brightest
thermal source seen on Io by New Horizons wasn’t
seen by Voyager in 1979, or Galileo in the late 1990s,
or indeed from any ground-based telescopes. East
Girru lies 200km from a hotspot that was seen by
Galileo, and so Rathbun has concluded that it’s a
new eruption. But, when comparing the highest-
resolution photos from Galileo and New Horizons
of the landscape around East Girru, she couldn’t
see any noticeable changes between the two, nor
any lighter region of the type that’s normally seen
around volcanic sites on Io. So this new intense
hotspot is something of a mystery: what’s the
source of all that activity?
Lewis DartneLL is an astrobiology research fellow at the University of Leicester. His new book The Knowledge will be published in April.
Lewis DartneLL was reading… Io’s active volcanoes during the New Horizons era: Insights from New Horizons imaging by J A rathbun et al. read it online at http://dx.doi.org/10.1016/ j.icarus.2013.12.002
Our experts examine the hottest new research
io seen through three new Horizons instruments; the tvashtar volcano near the moon’s north pole is the brightest hotspot in each image, with a temperature of 950°C
The violence of IoImages taken by the New Horizons probe are giving us a greater insight into this highly volcanic moon
CUTTING
EDGE
“Pele was glowing when it was frst detected by Voyager in 1979 and was still going strong in 2007”
Bulletin APRIL 17
skyatnightmagazine.com 2014
Heavy isotope titanium-44, imaged by NuSTAR and shown in blue, is clearly clustered at the centre of the explosion
What makes stars explode?NASA’s NuSTAR may have uncovered why stars become violently unstable
The mysTery of how stars explode might fnally
be solved. X-ray observations taken by NAsA’s
Nuclear spectroscopic Telescope Array (NusTAr)
suggest material in soon-to-explode stars sloshes
around violently, energising a shock wave
that blows the star to smithereens.
NusTAr was launched into
low-earth orbit in June
2012. Now it has created
the frst map of
radioactive material
in a supernova
remnant,
Cassiopeia A,
which lies
about 11,000
lightyears
from us.
Cassiopeia A
formed when
a massive star
exploded after
running out of
fuel; the light of this
detonation reached
earth roughly 300 years
ago. During the blast, high
temperatures made lighter
elements fuse into heavier ones,
and now NusTAr has created a
map of one of the heavy isotopes
in Cassiopeia A, titanium-44.
The map resolves some puzzles about
supernovae. During the explosion, a shock wave
somehow blasts the star apart, yet previous
computer simulations of this process failed to
replicate this. Instead they suggested that the
NA
SA
/JPL
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/StS
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main shock wave would stall, preventing the star
from shattering. NusTAr revealed that titanium
is concentrated in clumps at Cassiopeia A’s centre.
Astronomers conclude from this that material in
the former star sloshed around, re-energising
the shock wave that fnally made it
blast off its outer layers.
“stars are spherical
balls of gas, so you
might think that
when they end their
lives and explode,
that explosion
would look like
a uniform ball
expanding
out,” says
NusTAr
scientist fiona
harrison from
the California
Institute of
Technology. “our
new results show
how the explosion’s
engine is distorted,
possibly because the inner
regions literally slosh around
before detonating.”
The NusTAr map also casts
doubt on another model of
supernovae, in which a star
rotates rapidly enough to launch energetic jets
of gas that drive the explosion. Although there’s
evidence of jets in Cassiopeia A, NusTAr’s
observations suggest they did not trigger the blast.
www.nasa.gov/nustar
JoiN THe HuNT foR plANeTARy SySTemSNASA is asking for help in fnding embryonic planetary systems in observations from the Wide-feld Infrared Survey Explorer (WISE) spacecraft. There may be thousands lurking in the data, but they can only be found through human inspection, which poses a huge challenge.
“Volunteers will help the astronomical community discover new planetary nurseries that will become future targets for NASA’s Hubble Space Telescope and its successor, the James Webb Space Telescope,” says James Garvin from NASA’s Goddard Space Flight Center in Maryland.www.diskdetective.org
news in
brief
AT lAST: A GlobAl mAp of GANymedeMore than four centuries after its discovery, the Solar System’s largest moon – Jupiter’s Ganymede – fnally has a global map. Wes Patterson from the Johns Hopkins University in Maryland and colleagues compiled it using images from NASA’s Voyager and Galileo missions.
HoW STARS CARVE STRANGE NEbUlAELow-mAss sTArs like the sun can end their
lives as double-lobed planetary nebulae if they
have close companions, a new study suggests.
sun-like stars eventually puff out their
atmospheres to form a ghostly glowing cloud
of gas – a ‘planetary nebula’ – while the core
shrinks. These were once thought to be mostly
spherical, but some possess bipolar jets.
This, theorises eric Blackman of the University
of rochester in New york, could be due to the
gravitational infuence of a companion star or
massive planet. The crucial factor is that the pair
must be very close together.
www.rochester.eduimaged by the Hubble Space Telescope, this pre-planetary nebula’s bipolar jets are clear to see
Bulletin APRIL 17
skyatnightmagazine.com 2014
Heavy isotope titanium-44, imaged by NuSTAR and shown in blue, is clearly clustered at the centre of the explosion
What makes stars explode?NASA’s NuSTAR may have uncovered why stars become violently unstable
The mysTery of how stars explode might fnally
be solved. X-ray observations taken by NAsA’s
Nuclear spectroscopic Telescope Array (NusTAr)
suggest material in soon-to-explode stars sloshes
around violently, energising a shock wave
that blows the star to smithereens.
NusTAr was launched into
low-earth orbit in June
2012. Now it has created
the frst map of
radioactive material
in a supernova
remnant,
Cassiopeia A,
which lies
about 11,000
lightyears
from us.
Cassiopeia A
formed when
a massive star
exploded after
running out of
fuel; the light of this
detonation reached
earth roughly 300 years
ago. During the blast, high
temperatures made lighter
elements fuse into heavier ones,
and now NusTAr has created a
map of one of the heavy isotopes
in Cassiopeia A, titanium-44.
The map resolves some puzzles about
supernovae. During the explosion, a shock wave
somehow blasts the star apart, yet previous
computer simulations of this process failed to
replicate this. Instead they suggested that the
NA
SA
/JPL
-CA
LteC
h/C
XC
/SA
O,
NA
SA
/eSA
& V
ALe
Nti
N B
uJA
rr
ABA
L (O
BSer
VA
tOriO
AStr
ON
Om
iCO
NA
CiO
NA
L/SPA
iN)
NA
SA
/h
uBBLe
/StS
Ci,
uSG
S
main shock wave would stall, preventing the star
from shattering. NusTAr revealed that titanium
is concentrated in clumps at Cassiopeia A’s centre.
Astronomers conclude from this that material in
the former star sloshed around, re-energising
the shock wave that fnally made it
blast off its outer layers.
“stars are spherical
balls of gas, so you
might think that
when they end their
lives and explode,
that explosion
would look like
a uniform ball
expanding
out,” says
NusTAr
scientist fiona
harrison from
the California
Institute of
Technology. “our
new results show
how the explosion’s
engine is distorted,
possibly because the inner
regions literally slosh around
before detonating.”
The NusTAr map also casts
doubt on another model of
supernovae, in which a star
rotates rapidly enough to launch energetic jets
of gas that drive the explosion. Although there’s
evidence of jets in Cassiopeia A, NusTAr’s
observations suggest they did not trigger the blast.
www.nasa.gov/nustar
JoiN THe HuNT foR plANeTARy SySTemSNASA is asking for help in fnding embryonic planetary systems in observations from the Wide-feld Infrared Survey Explorer (WISE) spacecraft. There may be thousands lurking in the data, but they can only be found through human inspection, which poses a huge challenge.
“Volunteers will help the astronomical community discover new planetary nurseries that will become future targets for NASA’s Hubble Space Telescope and its successor, the James Webb Space Telescope,” says James Garvin from NASA’s Goddard Space Flight Center in Maryland.www.diskdetective.org
news in
brief
AT lAST: A GlobAl mAp of GANymedeMore than four centuries after its discovery, the Solar System’s largest moon – Jupiter’s Ganymede – fnally has a global map. Wes Patterson from the Johns Hopkins University in Maryland and colleagues compiled it using images from NASA’s Voyager and Galileo missions.
HoW STARS CARVE STRANGE NEbUlAELow-mAss sTArs like the sun can end their
lives as double-lobed planetary nebulae if they
have close companions, a new study suggests.
sun-like stars eventually puff out their
atmospheres to form a ghostly glowing cloud
of gas – a ‘planetary nebula’ – while the core
shrinks. These were once thought to be mostly
spherical, but some possess bipolar jets.
This, theorises eric Blackman of the University
of rochester in New york, could be due to the
gravitational infuence of a companion star or
massive planet. The crucial factor is that the pair
must be very close together.
www.rochester.eduimaged by the Hubble Space Telescope, this pre-planetary nebula’s bipolar jets are clear to see
Events season continues. At the
end of March (28th-31st) we are
at Kelling Heath in Norfolk for
the Spring Equinox Star Party -
see www.starparty.org Then April
26th-27th sees us at Astrocamp
in Wales - great fun, for details
see www.astrocamp.org.uk
June 7-8th is the International
Astronomy Show in Warwick-
shire - www.ukastroshow.com
- and Sunday June 22nd will be
International Sun Day - and we
will be in Regent’s Park in cen-
tral London with the Baker Street
Irregular Astronomers - see
www.bakerstreetastro.org.uk
Rest assured that we at The
Widescreen Centre learn from
every show that we do, and at all
the events we have lined up for
2014 (including the SW Astron-
omy Fair, Autumn Kelling Heath,
Kielder Star Camp and more..)
we will have some very special
offers, great new products, and
the best advice there is. Visit
www.widescreen-centre.co.uk
The Widescreen CentreAll the major brands
under one roof!
London’s Astronomy Showroom,
In Marylebone since 1971.
The widest range of telescopes
and Astronomy products in the
UK - and the best advice in
the industry, from experienced,
enthusiastic staff with a practical,
thorough understanding of how
to get you out there exploring the
Universe the way you want.
London’s Coolest
Astronomical Society
Kelling Heath Star Party, Norfolk
In Store. In the feld. At exhibitions.
At Star Parties. In the Park. On site.
Online. By phone. By email.
Relentlessly bringing you the latest,
the greatest, and the best value
Astronomy products on the market.
We’re always happy to talk Astronomy.
Whatever the season.
Widescreen supports The Baker Street Irregular Astronomers - London’s coolest Astronomical Society - meeting monthly in Regent’s Park. Chance to
Check out our products after dark and learn in a fun, friendly environment about this great hobby. See www.bakerstreetastro.org.uk for more details.
Power Lander
intro £2699.00
Exclusively
from
020
7935
2580
For details of the next meeting
see www.bakerstreetastro.org.uk
Sky-Watcher
200DPS HEQ5
Pro - £CALL
Lunar photo by Widescreen customer Richard Maun. Main BSIA image by Tom Kerss
Events season continues. At the
end of March (28th-31st) we are
at Kelling Heath in Norfolk for
the Spring Equinox Star Party -
see www.starparty.org Then April
26th-27th sees us at Astrocamp
in Wales - great fun, for details
see www.astrocamp.org.uk
June 7-8th is the International
Astronomy Show in Warwick-
shire - www.ukastroshow.com
- and Sunday June 22nd will be
International Sun Day - and we
will be in Regent’s Park in cen-
tral London with the Baker Street
Irregular Astronomers - see
www.bakerstreetastro.org.uk
Rest assured that we at The
Widescreen Centre learn from
every show that we do, and at all
the events we have lined up for
2014 (including the SW Astron-
omy Fair, Autumn Kelling Heath,
Kielder Star Camp and more..)
we will have some very special
offers, great new products, and
the best advice there is. Visit
www.widescreen-centre.co.uk
The Widescreen CentreAll the major brands
under one roof!
London’s Astronomy Showroom,
In Marylebone since 1971.
The widest range of telescopes
and Astronomy products in the
UK - and the best advice in
the industry, from experienced,
enthusiastic staff with a practical,
thorough understanding of how
to get you out there exploring the
Universe the way you want.
London’s Coolest
Astronomical Society
Kelling Heath Star Party, Norfolk
In Store. In the feld. At exhibitions.
At Star Parties. In the Park. On site.
Online. By phone. By email.
Relentlessly bringing you the latest,
the greatest, and the best value
Astronomy products on the market.
We’re always happy to talk Astronomy.
Whatever the season.
Widescreen supports The Baker Street Irregular Astronomers - London’s coolest Astronomical Society - meeting monthly in Regent’s Park. Chance to
Check out our products after dark and learn in a fun, friendly environment about this great hobby. See www.bakerstreetastro.org.uk for more details.
Power Lander
intro £2699.00
Exclusively
from
020
7935
2580
For details of the next meeting
see www.bakerstreetastro.org.uk
Sky-Watcher
200DPS HEQ5
Pro - £CALL
Lunar photo by Widescreen customer Richard Maun. Main BSIA image by Tom Kerss
what’s on april 19
skyatnightmagazine.com 2014
Our pick of the best events from around the UK
What’s on
AstroCamp 2014Brecon Beacons, Wales, 26-29 April
Twice a year, the small village of Cwmdu in the Brecon Beacons is invaded by astronomers when AstroCamp rolls into town. This month, the popular star party returns to this beautiful site – a designated Dark Sky Reserve.
As well as observing at night, the event will include talks, workshops and a pub quiz with astronomical prizes – including telescopes – to be won.
All activities plus a pitch for your tent or caravan are included in the price of a ticket (electricity can be supplied to your pitch for an extra cost) but if you’re planning on taking part in the evening observing festivities it’s worth bringing your own equipment; and remember, torches should be red light only. Tickets start at £38 per adult and £15 for children. www.astrocamp.org.uk
Whether you pitch or park, fnding room to pack your own equipment is advised
PICK OF THE MONTH
mArsThis month The Sky at Night will journey across the face of our planetary neighbour – Mars. For more than 10 years we’ve had a continuous presence on Mars, thanks to the Opportunity, Spirit and Curiosity rovers. Together they have changed our understanding of the Red Planet and redefned our search for extraterrestrial life.
*Check www.radiotimes.com as times may vary
Four, 13 April, 10pm (repeated Four, 17 April, 7.30pm)*
behind the scenes
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more listings online
visit our website at www.skyatnightmagazine.com/whats-on for the full list of this month’s events from around the country.
to ensure that your talks, observing evenings and star parties are included, please submit your event by flling in the submission form at the bottom of the page.
yuri’s Nightseething Observatory, Thwaite st mary, Norfolk, 12 April, 2pm onwards
Norwich Astronomical Society is just one of the astronomy groups in the UK hosting a Yuri’s Night party to celebrate the frst manned spacefight. With solar viewing, rocket making and more during the day,
plus observing at night, this is an event for all the family. Tickets cost £3.50 for adults and £1.50 for children. You can fnd out more at www.norwichastro.org.uk.
Active galactic NucleiAyton Village hall, scarborough 11 April, 7.30pm
Hear Dr Stuart Lumsden from Leeds University’s School of Physics and Astronomy discussing supermassive black holes at Scarborough and Ryedale Astronomical
Society this month. Discover how these celestial leviathans grow and the dramatic effect they have on the galaxies around them. Tickets are free for members, £2 for non-members. Visit www.scarborough-ryedale-as.org.uk.
ground-level images taken by the martian rovers have given us new insights
Being Caroline herschelThe herschel museum of Astronomy, Bath, 16 April to 18 December
This new exhibition at the Herschel Museum of Astronomy celebrates the life and work of William Herschel’s sister Caroline, an accomplished musician and astronomer in her own right. Admission is included in the general museum entry fee, which is £6 for adults and £3 for children. Find out more at www.herschelmuseum.org.uk.
what’s on april 19
skyatnightmagazine.com 2014
Our pick of the best events from around the UK
What’s on
AstroCamp 2014Brecon Beacons, Wales, 26-29 April
Twice a year, the small village of Cwmdu in the Brecon Beacons is invaded by astronomers when AstroCamp rolls into town. This month, the popular star party returns to this beautiful site – a designated Dark Sky Reserve.
As well as observing at night, the event will include talks, workshops and a pub quiz with astronomical prizes – including telescopes – to be won.
All activities plus a pitch for your tent or caravan are included in the price of a ticket (electricity can be supplied to your pitch for an extra cost) but if you’re planning on taking part in the evening observing festivities it’s worth bringing your own equipment; and remember, torches should be red light only. Tickets start at £38 per adult and £15 for children. www.astrocamp.org.uk
Whether you pitch or park, fnding room to pack your own equipment is advised
PICK OF THE MONTH
mArsThis month The Sky at Night will journey across the face of our planetary neighbour – Mars. For more than 10 years we’ve had a continuous presence on Mars, thanks to the Opportunity, Spirit and Curiosity rovers. Together they have changed our understanding of the Red Planet and redefned our search for extraterrestrial life.
*Check www.radiotimes.com as times may vary
Four, 13 April, 10pm (repeated Four, 17 April, 7.30pm)*
behind the scenes
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more listings online
visit our website at www.skyatnightmagazine.com/whats-on for the full list of this month’s events from around the country.
to ensure that your talks, observing evenings and star parties are included, please submit your event by flling in the submission form at the bottom of the page.
yuri’s Nightseething Observatory, Thwaite st mary, Norfolk, 12 April, 2pm onwards
Norwich Astronomical Society is just one of the astronomy groups in the UK hosting a Yuri’s Night party to celebrate the frst manned spacefight. With solar viewing, rocket making and more during the day,
plus observing at night, this is an event for all the family. Tickets cost £3.50 for adults and £1.50 for children. You can fnd out more at www.norwichastro.org.uk.
Active galactic NucleiAyton Village hall, scarborough 11 April, 7.30pm
Hear Dr Stuart Lumsden from Leeds University’s School of Physics and Astronomy discussing supermassive black holes at Scarborough and Ryedale Astronomical
Society this month. Discover how these celestial leviathans grow and the dramatic effect they have on the galaxies around them. Tickets are free for members, £2 for non-members. Visit www.scarborough-ryedale-as.org.uk.
ground-level images taken by the martian rovers have given us new insights
Being Caroline herschelThe herschel museum of Astronomy, Bath, 16 April to 18 December
This new exhibition at the Herschel Museum of Astronomy celebrates the life and work of William Herschel’s sister Caroline, an accomplished musician and astronomer in her own right. Admission is included in the general museum entry fee, which is £6 for adults and £3 for children. Find out more at www.herschelmuseum.org.uk.
A pAssion for spAce april 21
skyatnightmagazine.com 2014
The famous
tagline used to
advertise the
1979 flm
Alien was “In space no
one can hear you
scream”. Technically,
that’s true. In the
vacuum of space sound
waves are unable to
propagate as there’s no
medium to carry them.
So why are the sounds of
the Universe the subject
of March’s episode of
The Sky at Night? Well,
it’s because sound has
helped us discover some
amazing things about
celestial bodies and may
help us solve one of the mysteries that
continues to puzzle us.
Good vibrationsMy frst encounter with sounds in space
came with the Cassini-Huygens space
probe. After its seven-year journey of
more than 1.5 billion km the spacecraft
arrived at Saturn and released the Huygens
lander, which tumbled through the dense
atmosphere of Saturn’s moon Titan. It
sent back sounds and images as it fell, and
I remember being amazed at hearing
sounds from bodies in our Solar System.
Now we’re doing more with sound and
we don’t have to send up a spacecraft to
detect it, as vibrations emanating from a
body can sometimes be seen. In the early
1960s oscillations were observed over the thin
kst
oc
k
a passion for
Listen carefully: sound could help us solve one of the enduring mysteries of the Universe
surface of the Sun. The oscillations were
detected by measurements of red or blue
shifts of small surface patches, which were
able to tell us if the area being observed
was moving towards or away from us.
The source of the oscillations was
unknown at the time and it was suggested
that they were due to sound waves
generated inside the Sun. Observations
later confrmed this and the science of
helioseismology was born. Just as
seismologists here on Earth can use
tectonic events to probe our planet’s
interior, so similar techniques can be used
to probe the Sun and reveal structure that
we otherwise could not see.
Now it’s hoped that oscillations
generated by other objects in space could
be used to detect one of the true enigmas
of modern physics:
gravitational waves.
The demise of a star
can leave behind some
interesting debris. Some
leave a white dwarf,
some collapse to form
black holes while others
turn supernova and can
leave behind a neutron
star – a body the size of
a city (~10km) with the
mass a little less than
1.5 times that of our Sun.
A pulsar is a type of
neutron star that emits a
beam of radiation that
appears to pulsate – a bit
like the light from a
lighthouse – due to a
misalignment between its rotational and
magnetic axes. If this beam is in the right
orientation, its radio waves can be detected
on Earth and heard as a clicking sound.
The frequency of the clicking can be
incredibly stable. So stable, in fact, that it
may enable us to detect a gravitational
wave, as a wave’s presence could cause a
minuscule delay in the arrival the pulse’s
clicks on Earth. If a delay is found in a
number of pulsars then the passing of a
gravitational wave could be detected.
So even if screaming is futile, listening is
not, as the detection of sound waves and
oscillations out there is giving us new
insight into the Universe around us.
Maggie Aderin-Pocock is a space scientist and co-presenter of The Sky at Night
with Maggie Aderin-Pocock
S
The audible ‘footprint’ of a gravitational wave could be detected in a pulsar’s radiation beam
A pAssion for spAce april 21
skyatnightmagazine.com 2014
The famous
tagline used to
advertise the
1979 flm
Alien was “In space no
one can hear you
scream”. Technically,
that’s true. In the
vacuum of space sound
waves are unable to
propagate as there’s no
medium to carry them.
So why are the sounds of
the Universe the subject
of March’s episode of
The Sky at Night? Well,
it’s because sound has
helped us discover some
amazing things about
celestial bodies and may
help us solve one of the mysteries that
continues to puzzle us.
Good vibrationsMy frst encounter with sounds in space
came with the Cassini-Huygens space
probe. After its seven-year journey of
more than 1.5 billion km the spacecraft
arrived at Saturn and released the Huygens
lander, which tumbled through the dense
atmosphere of Saturn’s moon Titan. It
sent back sounds and images as it fell, and
I remember being amazed at hearing
sounds from bodies in our Solar System.
Now we’re doing more with sound and
we don’t have to send up a spacecraft to
detect it, as vibrations emanating from a
body can sometimes be seen. In the early
1960s oscillations were observed over the thin
kst
oc
k
a passion for
Listen carefully: sound could help us solve one of the enduring mysteries of the Universe
surface of the Sun. The oscillations were
detected by measurements of red or blue
shifts of small surface patches, which were
able to tell us if the area being observed
was moving towards or away from us.
The source of the oscillations was
unknown at the time and it was suggested
that they were due to sound waves
generated inside the Sun. Observations
later confrmed this and the science of
helioseismology was born. Just as
seismologists here on Earth can use
tectonic events to probe our planet’s
interior, so similar techniques can be used
to probe the Sun and reveal structure that
we otherwise could not see.
Now it’s hoped that oscillations
generated by other objects in space could
be used to detect one of the true enigmas
of modern physics:
gravitational waves.
The demise of a star
can leave behind some
interesting debris. Some
leave a white dwarf,
some collapse to form
black holes while others
turn supernova and can
leave behind a neutron
star – a body the size of
a city (~10km) with the
mass a little less than
1.5 times that of our Sun.
A pulsar is a type of
neutron star that emits a
beam of radiation that
appears to pulsate – a bit
like the light from a
lighthouse – due to a
misalignment between its rotational and
magnetic axes. If this beam is in the right
orientation, its radio waves can be detected
on Earth and heard as a clicking sound.
The frequency of the clicking can be
incredibly stable. So stable, in fact, that it
may enable us to detect a gravitational
wave, as a wave’s presence could cause a
minuscule delay in the arrival the pulse’s
clicks on Earth. If a delay is found in a
number of pulsars then the passing of a
gravitational wave could be detected.
So even if screaming is futile, listening is
not, as the detection of sound waves and
oscillations out there is giving us new
insight into the Universe around us.
Maggie Aderin-Pocock is a space scientist and co-presenter of The Sky at Night
with Maggie Aderin-Pocock
S
The audible ‘footprint’ of a gravitational wave could be detected in a pulsar’s radiation beam
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ADVERTISEMENT FEATURE
Here’s a great selection of places to stay where you can relax in comfort and enjoy the experience of dark sky observations
DARK SKY
Destinations
Located deep in the
heart of darkest
Northumberland
close to the Sir Patrick
Moore Observatory,
Kielder Water and
Forest Park with
heavenly dark skies.
01434 240 382 • www.thepheasantinn.com
stay@thepheasantinn.com
THe PHeasanT InnKIelder WaTer
This B&B accommodation
is near the UK’s frst dark
sky park. There are a
range of telescopes, and
courses for beginners.
Children and pets
welcome.
From only £26 pppn.
01988 500594 • www.gallowayastro.com enquiries@gallowayastro.com
GalloWay asTronomy CenTre
Galloway
GallowayForest Parkhome to the UK’s onlyDark Sky Park
For more information visit our websiteor call us on 01671 402420www.forestry.gov.uk/darkskygalloway
Imagine a sky full of stars, darkness all around with only nature as your companion.
Bortle class 2, the Milky Way, good food,
Imagine no more, it's here!
Grab your binoculars and visit the UK's only Dark Sky Park. Scotland's Heavenly Wonder.
fabulous wildlife, amazing events and a great welcome.
01550 750264 • www.cambrianway.com
info@cambrianway.com
llanerCHIndda Farm
This 3-star guest house and its self -catering cottages look
on to the Brecon Beacons that have just been given Dark
Sky Status. We are also the perfect base for exploring and
enjoying the beautiful heartland of Wales.
ma
in ill
ustr
ati
on
by m
ark
ga
rli
ck
, ph
oto
: Em
ma
sa
mm
s
Sitting at the controls of the
Cruiser globe, i’m gripped by an urge
to experience the unfathomable infnity
of the Universe. Such an overused word,
‘awesome’: reasonably priced Florida
doughnuts may be described in a twangy
Miley Cyrus tone as ‘awesome’, but the
vastness of the Universe is awesomeness
in the true sense. i hit launch and head
off in a random direction.
Soon the Cruiser globe’s scanning
systems indicate an unknown object.
i feel a concern similar to Captain
Phillips when he spotted the Somali
pirates looming. But drawing closer,
the great mystery is revealed: this object
is a rogue planet. a solitary world
drifting through the Universe, devoid
of a parent star.
there’s a tantalising blend of
fascination and foreboding on
approaching this world that was
somehow ejected from its system,
perhaps by a gravitational encounter
with another object. it’s estimated there
are around two rogue planets for every
star in the galaxy. Some scientists
think there may be many more.
a technique called gravitational
microlensing is used to detect rogue
planets back on earth, but there’s no need
for such methods today as this particular
rogue planet is right in front of me. i land
immediately to experience the feeling of
this lonesome world.
the view from the surface is a palette
of charcoal grey and opaque blackness,
like my grandmother’s monochrome
Pye tV with the brightness at minimum.
this is a rocky world interspersed with
features resembling massive lakes of ice.
if there’s radioactive decay happening
in the planet’s core, it might generate
enough heat for the lakes to be liquifed
deeper down.
there are those who believe it’s
possible for earth-sized wandering
planets like this one to retain an
atmosphere, perhaps of thick hydrogen.
Combine this with enough subterranean
geological activity and there could be
suffcient warmth generated to support
life. these disconnected planets are not
without the most intriguing potential.
this alien sky of the deepest blackness
has stars so magnifcently piercing that
they cast shadows. it’s novel to notice that
the stars in this rogue planet’s sky never
move. Very soon it’s disconcerting, even
frustrating that the entire night sky here is
an unvarying, motionless mural. Due to
not being in a conventional orbit and
because any rotation of this planet on its
axis has become so imperceptibly slow, the
stars in this alien sky wouldn’t appear to
change in an entire human lifetime. Sir
Patrick would’ve had this dark sky entirely
observed, sketched and catalogued in
under a week, leaving him plenty of time
for cricket and a g&t in the pavilion.
this desolate place conveys a strange
feeling of sadness. it seems impossible
not to project human emotions onto this
environment. Feeling pity for a planet:
what a bizarre sensation. i decide to
name this lonely world ‘Obsidiana’.
in my imagination i hear the piano
theme from the Bill Bixby-era Incredible
Hulk tV show as the rogue planet
Obsidiana drifts silently through the
Universe in her own sweet way.
Jon Culshaw is a comedian, impressionist and occasional guest on The Sky at Night
ex planetjon culshaw’s
exoplanet excursions april 23
jon fnds himself on a world so steeped in darkness that the stars cast shadows
excursions
ma
in ill
ustr
ati
on
by m
ark
ga
rli
ck
, ph
oto
: Em
ma
sa
mm
s
Sitting at the controls of the
Cruiser globe, i’m gripped by an urge
to experience the unfathomable infnity
of the Universe. Such an overused word,
‘awesome’: reasonably priced Florida
doughnuts may be described in a twangy
Miley Cyrus tone as ‘awesome’, but the
vastness of the Universe is awesomeness
in the true sense. i hit launch and head
off in a random direction.
Soon the Cruiser globe’s scanning
systems indicate an unknown object.
i feel a concern similar to Captain
Phillips when he spotted the Somali
pirates looming. But drawing closer,
the great mystery is revealed: this object
is a rogue planet. a solitary world
drifting through the Universe, devoid
of a parent star.
there’s a tantalising blend of
fascination and foreboding on
approaching this world that was
somehow ejected from its system,
perhaps by a gravitational encounter
with another object. it’s estimated there
are around two rogue planets for every
star in the galaxy. Some scientists
think there may be many more.
a technique called gravitational
microlensing is used to detect rogue
planets back on earth, but there’s no need
for such methods today as this particular
rogue planet is right in front of me. i land
immediately to experience the feeling of
this lonesome world.
the view from the surface is a palette
of charcoal grey and opaque blackness,
like my grandmother’s monochrome
Pye tV with the brightness at minimum.
this is a rocky world interspersed with
features resembling massive lakes of ice.
if there’s radioactive decay happening
in the planet’s core, it might generate
enough heat for the lakes to be liquifed
deeper down.
there are those who believe it’s
possible for earth-sized wandering
planets like this one to retain an
atmosphere, perhaps of thick hydrogen.
Combine this with enough subterranean
geological activity and there could be
suffcient warmth generated to support
life. these disconnected planets are not
without the most intriguing potential.
this alien sky of the deepest blackness
has stars so magnifcently piercing that
they cast shadows. it’s novel to notice that
the stars in this rogue planet’s sky never
move. Very soon it’s disconcerting, even
frustrating that the entire night sky here is
an unvarying, motionless mural. Due to
not being in a conventional orbit and
because any rotation of this planet on its
axis has become so imperceptibly slow, the
stars in this alien sky wouldn’t appear to
change in an entire human lifetime. Sir
Patrick would’ve had this dark sky entirely
observed, sketched and catalogued in
under a week, leaving him plenty of time
for cricket and a g&t in the pavilion.
this desolate place conveys a strange
feeling of sadness. it seems impossible
not to project human emotions onto this
environment. Feeling pity for a planet:
what a bizarre sensation. i decide to
name this lonely world ‘Obsidiana’.
in my imagination i hear the piano
theme from the Bill Bixby-era Incredible
Hulk tV show as the rogue planet
Obsidiana drifts silently through the
Universe in her own sweet way.
Jon Culshaw is a comedian, impressionist and occasional guest on The Sky at Night
ex planetjon culshaw’s
exoplanet excursions april 23
jon fnds himself on a world so steeped in darkness that the stars cast shadows
excursions
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Sky at NightmagaziNe
The perfect addition to your stargazing, BBC Sky at Night Magazine is your practical guide to astronomy, helping you to discover the night skies, understand the Universe around us and
learn exciting techniques for using your telescope.
have BBC Sky at Night Magazine delivered straight to your device
When you take out a one month free trial* Simply return to homepage to subscribe
*After your one month trial your subscription will continue at £2.99 per month
Sky at NightmagaziNe
26
Interactive
skyatnightmagazine.com 2014
Email us at inbox@skyatnightmagazine.com
message of the month Mad about MaggieThe more I see her on TV, the more my admiration
for Dr Maggie Aderin-Pocock grows. Her obvious
enthusiasm is contagious and engaging – she lights
up the screen every time she appears. Something
she seems to share with the late, great Sir Patrick is
her ability to speak plain English, even when going
into technical detail.
When I heard she was to become a Sky at Night
presenter in February, I was thrilled. I believe she
will be a great ambassador for astronomy and a
superb role model for the young. I’m looking
forward to the next episode of The Sky at Night
and wish Maggie all the best.
Also, thanks for Stephen Tonkin’s Binocular
tour, it’s been a godsend on these stormy nights
whenever there’s been a brief break in the clouds.
The skies seem to have been really clear despite
all the foul weather!
George Futers, Peebles
We agree George, don’t forget to read Maggie’s excellent column on page 21. – Ed
Catch them youngOn Sunday morning recently I had an hour free
before lunch to read BBC Sky at Night Magazine. But
within 10 minutes that idea was shattered, as my
daughter arrived for a visit, bringing my seven-
month-old granddaughter Emily with her. Emily
made herself comfortable on my knee and
proceeded to cast her eyes over the page I was
reading. After a while, she
lost interest and opted for
the more interesting task of
riding the hobbyhorse. I did
my best to guide her towards
the astronomy path, but
maybe it was a bit too early!
Geoff Wadsley,
Wellingborough
Maybe seven months is a bit ambitious Geoff, but don’t give up yet! – Ed
new uses for old scopesHow saddened I was to learn via Govert Schilling’s
article (‘Observing in an uncertain future’, March)
just how many perfectly serviceable – and sizeable
– telescopes in Chile are being mothballed or
decommissioned. What a waste.
I imagine I’m not the only reader to have made a
connection between that and Kieron Allen’s piece
about robotic scopes (‘Imaging from afar’) later in
the same issue. Couldn’t some of the Chilean
observatories be added to those that are already
remotely accessible to fee-paying users? Although
perhaps there’s another potential use these
telescopes could be put to?
There is a growing realisation and acceptance
that near-Earth objects (NEOs) are far more
numerous than previously thought, and that
even relatively small ones are capable of doing
extreme damage to our planet. Britain has its own
Spaceguard Centre on the English-Welsh border
and there are others scattered around the world
Emails • lEttErs • twEEts • FaCEBOOK
The ‘Message of the Month’ writer will receive four top titles courtesy of astronomy publisher Philip’s. Heather Couper and Nigel Henbest’s Stargazing 2014 is a month-by-month guide to the year and you’ll be able to fnd all the best sights with Patrick Moore’s The Night Sky. Stargazing with Binoculars by Robin Scagell and David Frydman contains equipment and observing guides, and you’ll be viewing planets, galaxies and more with Storm Dunlop’s Practical Astronomy.
this month’s top prize: four Philip’s books
Þ Dr Maggie Aderin-Pocock is skilled at communicating her knowledge of and enthusiasm for astronomy
þ Seven-month-old Emily gets to grips with BBC Sky at Night Magazine
bbc
26
Interactive
skyatnightmagazine.com 2014
Email us at inbox@skyatnightmagazine.com
message of the month Mad about MaggieThe more I see her on TV, the more my admiration
for Dr Maggie Aderin-Pocock grows. Her obvious
enthusiasm is contagious and engaging – she lights
up the screen every time she appears. Something
she seems to share with the late, great Sir Patrick is
her ability to speak plain English, even when going
into technical detail.
When I heard she was to become a Sky at Night
presenter in February, I was thrilled. I believe she
will be a great ambassador for astronomy and a
superb role model for the young. I’m looking
forward to the next episode of The Sky at Night
and wish Maggie all the best.
Also, thanks for Stephen Tonkin’s Binocular
tour, it’s been a godsend on these stormy nights
whenever there’s been a brief break in the clouds.
The skies seem to have been really clear despite
all the foul weather!
George Futers, Peebles
We agree George, don’t forget to read Maggie’s excellent column on page 21. – Ed
Catch them youngOn Sunday morning recently I had an hour free
before lunch to read BBC Sky at Night Magazine. But
within 10 minutes that idea was shattered, as my
daughter arrived for a visit, bringing my seven-
month-old granddaughter Emily with her. Emily
made herself comfortable on my knee and
proceeded to cast her eyes over the page I was
reading. After a while, she
lost interest and opted for
the more interesting task of
riding the hobbyhorse. I did
my best to guide her towards
the astronomy path, but
maybe it was a bit too early!
Geoff Wadsley,
Wellingborough
Maybe seven months is a bit ambitious Geoff, but don’t give up yet! – Ed
new uses for old scopesHow saddened I was to learn via Govert Schilling’s
article (‘Observing in an uncertain future’, March)
just how many perfectly serviceable – and sizeable
– telescopes in Chile are being mothballed or
decommissioned. What a waste.
I imagine I’m not the only reader to have made a
connection between that and Kieron Allen’s piece
about robotic scopes (‘Imaging from afar’) later in
the same issue. Couldn’t some of the Chilean
observatories be added to those that are already
remotely accessible to fee-paying users? Although
perhaps there’s another potential use these
telescopes could be put to?
There is a growing realisation and acceptance
that near-Earth objects (NEOs) are far more
numerous than previously thought, and that
even relatively small ones are capable of doing
extreme damage to our planet. Britain has its own
Spaceguard Centre on the English-Welsh border
and there are others scattered around the world
Emails • lEttErs • twEEts • FaCEBOOK
The ‘Message of the Month’ writer will receive four top titles courtesy of astronomy publisher Philip’s. Heather Couper and Nigel Henbest’s Stargazing 2014 is a month-by-month guide to the year and you’ll be able to fnd all the best sights with Patrick Moore’s The Night Sky. Stargazing with Binoculars by Robin Scagell and David Frydman contains equipment and observing guides, and you’ll be viewing planets, galaxies and more with Storm Dunlop’s Practical Astronomy.
this month’s top prize: four Philip’s books
Þ Dr Maggie Aderin-Pocock is skilled at communicating her knowledge of and enthusiasm for astronomy
þ Seven-month-old Emily gets to grips with BBC Sky at Night Magazine
bbc
letters APRIL 27
skyatnightmagazine.com 2014
Have your say at http://twitter.com/skyatnightmag
@skyatnightmag
asked: How have
you made the most of the
rare breaks in the clouds
this stormy season?
@Ripley180924609
By being able to watch
as the #ISS passed over
– frst time I’ve ever seen
it and it was fab. :-)
@sjb_astro
Left scope all set up in
garage ready to quickly
take out during rare
clear spells. Observed
SN 2014J, Jupiter and
the Moon.
@thephildoyle
I read a billion reviews
and blogs to shortlist the
best planetary camera,
new or used, for circa
£200.
@EardleyTony
Imaged a new once-
in-a-lifetime supernova
in M82.
@haddockman83
Had a good look at the
Moon through binoculars
and managed to see the
rings of Jupiter through
a telescope.
@smyth791
As soon as the clouds
break, I have been out
looking at Jupiter and
its amazing moons. :)
the big
debate
EDITORIALEditor Chris Bramley Art Editor Steve MarshProduction Editor Kev Lochun Online Editor Kieron AllenStaff Writer Elizabeth PearsonReviews Editor Paul Money
CONTRIBUTORS Paul Abel, Sean Blair, Paul F Cockburn, Adam Crute, Maggie Aderin-Pocock, Jon Culshaw, Lewis Dartnell, Glenn Dawes, Mark Garlick, Will Gater, Alastair Gunn, Nicky Guttridge, Carol Lakomiak, Pete Lawrence, Martin Lewis, Chris Lintott, Hazel Muir, Steve Richards, Steve Sayers, Paul Sutherland, Stephen Tonkin, Emily Winterburn
ADVERTISING SALESAdvertising Director Caroline HerbertAdvertising Managers Steve Grigg (0117 314 8365), Tony Robinson (0117 314 8811)Inserts Laurence Robertson (00 353 87 690 2208)
PRODUCTIONProduction Director Sarah Powell Production Manager Derrick AndrewsAd Services Manager Paul ThorntonAd Co-ordinator Emily ThorneAd Designers Cee Pike, Andrew HobsonReprographics Tony Hunt, Chris Sutch
LICENSINGHead of Licensing and Syndication Joanna Marshall
MARKETINGHead of Circulation Rob Brock Head of Marketing Jacky Perales-MorrisMarketing Executive Chris DayHead of Press and PR Carolyn Wray (0117 314 8812)
PUBLISHINGPublisher Jemima RansomeManaging Director Andy Marshall
MANAGEMENT Chairman Stephen Alexander Deputy Chairman Peter PhippenCEO Tom Bureau
BBC WORLDWIDE, UK PUBLISHINGDirector of UK Publishing Nicholas Brett Head of UK Publishing Chris KerwinHead of Editorial, UK Publishing Jenny PotterUK Publishing Coordinator Eva Abramik UK.Publishing@bbc.com www.bbcworldwide.com/uk--anz/ukpublishing.aspx
EDITORIAL ADVISORY BOARD Deborah Cohen, Andrew Cohen, Michael Ewing, Julian Hector, John Lynch, Jonathan Renouf
SUBSCRIPTION RATESAnnual subscription rates (inc P&P): UK cheque/credit card £59.88; Europe & Eire
Airmail £69; rest of world airmail £79. To order, call 0844 844 0260
The publisher, editor and authors accept no responsibility in respect of any products, goods or services that may be advertised or referred to in this issue for any errors, omissions, mis-statements or mistakes in any such advertisements or references.
BBC Sky at Night Magazine is published by Immediate Media Company Bristol Limited under licence from BBC Worldwide, who help fund new BBC programmes.
that report newly identifed NEOs to a centre in
Boston, US.My understanding is that there is a
shortage of telescopes that are large enough to
be able to see these smaller objects dedicated
to this important area of observation. I wonder
if the Chilean ones might be pressed
into service?
David Tart, Walsall
Great idea David, it would be real shame to let these historic observatories close down altogether. – Ed
a successful comebackBack in the late 1950s and early 1960s, I was bitten
by the space and astronomy bug. But, as with many
young people, this all came to an end when I
fnished school and went out into the big wide
world. Now, newly retired, I’ve returned to the fold.
I quickly realised that science and technology
have moved on a great deal in the 50 years since I
last gazed up at the sky, so I began looking around
for a suitable magazine that would help me learn
about astronomy today. That’s when I found BBC
Sky at Night Magazine. Its balance of recurring
sections such as the Guide to the Universe and the
Big Questions, combined with observing tips,
monthly charts and excellent articles have all helped
enormously to rekindle my interest.
With a background in communications, I’ve
decided to delve into the world of radio astronomy.
Apart from anything else, it means I don’t have to
go out into the cold! In the few months that I’ve
been reading your excellent magazine, there hasn’t
been anything on the subject. Do you have any
plans to cover the topic?
Brian Faulkner, Cornwall
I’m glad we’ve been able to help rekindle you passion for astronomy Brian. Keep your eyes peeled for our How to… article on radio meteor observations coming up in next month’s issue. – Ed
Caught on cameraThis is a picture I took with
just my refractor scope and
my camera phone. I didn’t
use any Moon flters.
Alisia Maldon-Stanley (aged 15),
London
What a fantastic shot Alisia, keep going with the astrophotography, you’ve obviously got a talent. – Ed
© Immediate Media Company Bristol Limited 2014ISSN 1745-9869All rights reserved. No part of BBC Sky at Night Magazine may be reproduced in any form or by means either wholly or in part, without prior written permission of the publisher. Not to be re-sold, lent or hired out or otherwise disposed of by way of trade at more than the recommended retail price (subject to VAT in the Republic of Ireland) or in mutilated condition.
Immediate Media Company Bristol Limited is working to ensure that all of its paper is sourced from well-managed forests. This magazine is printed on Forest Stewardship Council (FSC) certifed paper. This magazine can be recycled, for use in newspapers and packaging. Please remove any gifts, samples or wrapping and dispose of it at your local collection point.
.........................................................................................OOPS!• In March 2014’s First Light review of the Celestron Skyris 445C colour imaging camera, the overall score should have been four stars, not three.
READER SURVEY WINNERCongratulations to the winner of our reader survey prize draw in the December 2013 issue. Andy Offord from Stowmarket, Suffolk, wins a 16GB iPad Mini.
letters APRIL 27
skyatnightmagazine.com 2014
Have your say at http://twitter.com/skyatnightmag
@skyatnightmag
asked: How have
you made the most of the
rare breaks in the clouds
this stormy season?
@Ripley180924609
By being able to watch
as the #ISS passed over
– frst time I’ve ever seen
it and it was fab. :-)
@sjb_astro
Left scope all set up in
garage ready to quickly
take out during rare
clear spells. Observed
SN 2014J, Jupiter and
the Moon.
@thephildoyle
I read a billion reviews
and blogs to shortlist the
best planetary camera,
new or used, for circa
£200.
@EardleyTony
Imaged a new once-
in-a-lifetime supernova
in M82.
@haddockman83
Had a good look at the
Moon through binoculars
and managed to see the
rings of Jupiter through
a telescope.
@smyth791
As soon as the clouds
break, I have been out
looking at Jupiter and
its amazing moons. :)
the big
debate
EDITORIALEditor Chris Bramley Art Editor Steve MarshProduction Editor Kev Lochun Online Editor Kieron AllenStaff Writer Elizabeth PearsonReviews Editor Paul Money
CONTRIBUTORS Paul Abel, Sean Blair, Paul F Cockburn, Adam Crute, Maggie Aderin-Pocock, Jon Culshaw, Lewis Dartnell, Glenn Dawes, Mark Garlick, Will Gater, Alastair Gunn, Nicky Guttridge, Carol Lakomiak, Pete Lawrence, Martin Lewis, Chris Lintott, Hazel Muir, Steve Richards, Steve Sayers, Paul Sutherland, Stephen Tonkin, Emily Winterburn
ADVERTISING SALESAdvertising Director Caroline HerbertAdvertising Managers Steve Grigg (0117 314 8365), Tony Robinson (0117 314 8811)Inserts Laurence Robertson (00 353 87 690 2208)
PRODUCTIONProduction Director Sarah Powell Production Manager Derrick AndrewsAd Services Manager Paul ThorntonAd Co-ordinator Emily ThorneAd Designers Cee Pike, Andrew HobsonReprographics Tony Hunt, Chris Sutch
LICENSINGHead of Licensing and Syndication Joanna Marshall
MARKETINGHead of Circulation Rob Brock Head of Marketing Jacky Perales-MorrisMarketing Executive Chris DayHead of Press and PR Carolyn Wray (0117 314 8812)
PUBLISHINGPublisher Jemima RansomeManaging Director Andy Marshall
MANAGEMENT Chairman Stephen Alexander Deputy Chairman Peter PhippenCEO Tom Bureau
BBC WORLDWIDE, UK PUBLISHINGDirector of UK Publishing Nicholas Brett Head of UK Publishing Chris KerwinHead of Editorial, UK Publishing Jenny PotterUK Publishing Coordinator Eva Abramik UK.Publishing@bbc.com www.bbcworldwide.com/uk--anz/ukpublishing.aspx
EDITORIAL ADVISORY BOARD Deborah Cohen, Andrew Cohen, Michael Ewing, Julian Hector, John Lynch, Jonathan Renouf
SUBSCRIPTION RATESAnnual subscription rates (inc P&P): UK cheque/credit card £59.88; Europe & Eire
Airmail £69; rest of world airmail £79. To order, call 0844 844 0260
The publisher, editor and authors accept no responsibility in respect of any products, goods or services that may be advertised or referred to in this issue for any errors, omissions, mis-statements or mistakes in any such advertisements or references.
BBC Sky at Night Magazine is published by Immediate Media Company Bristol Limited under licence from BBC Worldwide, who help fund new BBC programmes.
that report newly identifed NEOs to a centre in
Boston, US.My understanding is that there is a
shortage of telescopes that are large enough to
be able to see these smaller objects dedicated
to this important area of observation. I wonder
if the Chilean ones might be pressed
into service?
David Tart, Walsall
Great idea David, it would be real shame to let these historic observatories close down altogether. – Ed
a successful comebackBack in the late 1950s and early 1960s, I was bitten
by the space and astronomy bug. But, as with many
young people, this all came to an end when I
fnished school and went out into the big wide
world. Now, newly retired, I’ve returned to the fold.
I quickly realised that science and technology
have moved on a great deal in the 50 years since I
last gazed up at the sky, so I began looking around
for a suitable magazine that would help me learn
about astronomy today. That’s when I found BBC
Sky at Night Magazine. Its balance of recurring
sections such as the Guide to the Universe and the
Big Questions, combined with observing tips,
monthly charts and excellent articles have all helped
enormously to rekindle my interest.
With a background in communications, I’ve
decided to delve into the world of radio astronomy.
Apart from anything else, it means I don’t have to
go out into the cold! In the few months that I’ve
been reading your excellent magazine, there hasn’t
been anything on the subject. Do you have any
plans to cover the topic?
Brian Faulkner, Cornwall
I’m glad we’ve been able to help rekindle you passion for astronomy Brian. Keep your eyes peeled for our How to… article on radio meteor observations coming up in next month’s issue. – Ed
Caught on cameraThis is a picture I took with
just my refractor scope and
my camera phone. I didn’t
use any Moon flters.
Alisia Maldon-Stanley (aged 15),
London
What a fantastic shot Alisia, keep going with the astrophotography, you’ve obviously got a talent. – Ed
© Immediate Media Company Bristol Limited 2014ISSN 1745-9869All rights reserved. No part of BBC Sky at Night Magazine may be reproduced in any form or by means either wholly or in part, without prior written permission of the publisher. Not to be re-sold, lent or hired out or otherwise disposed of by way of trade at more than the recommended retail price (subject to VAT in the Republic of Ireland) or in mutilated condition.
Immediate Media Company Bristol Limited is working to ensure that all of its paper is sourced from well-managed forests. This magazine is printed on Forest Stewardship Council (FSC) certifed paper. This magazine can be recycled, for use in newspapers and packaging. Please remove any gifts, samples or wrapping and dispose of it at your local collection point.
.........................................................................................OOPS!• In March 2014’s First Light review of the Celestron Skyris 445C colour imaging camera, the overall score should have been four stars, not three.
READER SURVEY WINNERCongratulations to the winner of our reader survey prize draw in the December 2013 issue. Andy Offord from Stowmarket, Suffolk, wins a 16GB iPad Mini.
28
skyatnightmagazine.com 2014
This month’s pick of your very best astrophotos
PHOTO
OF THEMONTH
Hotshots
Anna says: “I like this image as it shows just how much dust is around the Orion Complex, the dynamic range of this nebula and the large array of colours in the region that you don’t see well when viewing through an eyepiece. It also shows what can be imaged even with modest equipment given some patience and time.” Equipment: Nikon D7000 DSLR camera, Orion EON 80ED telescope.
BBC Sky at Night Magazine says: “The amount of detail Anna has been able to capture in this pristine image of the Orion Nebula and its surroundings is amazing. We very rarely see wide-feld images of this corner of space that manage, so expertly, to defne the intricate dust lanes on the periphery of the central nebulous region. From vibrant pinks and blues to the pastel, almost muddy, hues of the dust lanes, this is the work of an expert.”
About Anna: “I started astro imaging back in 2008. I was living in a light-polluted area and could not see much through the new scope I had got for Christmas due to all the city lights. Short exposure
images allowed me to make out more than I could through the eyepiece. I got the bug from those frst photographs and have been imaging since.”
The Orion Nebula
ANNA MORRIS, SuFFOLk, 5 DECEMbER 2013
28
skyatnightmagazine.com 2014
This month’s pick of your very best astrophotos
PHOTO
OF THEMONTH
Hotshots
Anna says: “I like this image as it shows just how much dust is around the Orion Complex, the dynamic range of this nebula and the large array of colours in the region that you don’t see well when viewing through an eyepiece. It also shows what can be imaged even with modest equipment given some patience and time.” Equipment: Nikon D7000 DSLR camera, Orion EON 80ED telescope.
BBC Sky at Night Magazine says: “The amount of detail Anna has been able to capture in this pristine image of the Orion Nebula and its surroundings is amazing. We very rarely see wide-feld images of this corner of space that manage, so expertly, to defne the intricate dust lanes on the periphery of the central nebulous region. From vibrant pinks and blues to the pastel, almost muddy, hues of the dust lanes, this is the work of an expert.”
About Anna: “I started astro imaging back in 2008. I was living in a light-polluted area and could not see much through the new scope I had got for Christmas due to all the city lights. Short exposure
images allowed me to make out more than I could through the eyepiece. I got the bug from those frst photographs and have been imaging since.”
The Orion Nebula
ANNA MORRIS, SuFFOLk, 5 DECEMbER 2013
HOTSHOTS APRIL 29
skyatnightmagazine.com 2014
The leaping puma in the Rosette Nebula
kFIR SIMON, GAN-YAvNE, ISRAEL 18,30 AND 31 JANuARY 2014
kfr says: “I like this image because of all the dark nebulae in the lower part of the frame, which resemble a parade of animals.“
Equipment: SbIG ST8300M CCD camera, Altair Astro 8-inch Ritchey-Chrétien astrograph, ASA DDM 60 PRO direct drive mount.
Jupiter and Europa
TOM HOWARD, SuSSEx, 9 DECEMbER 2013
Tom says: “I have never been interested in the expense and extra effort required in using colour flters for imaging. This image showed me what can be achieved with a one-shot colour planetary camera under excellent seeing conditions.”
Equipment: Celestron Skyris 618C CCD camera, Celestron C11 Schmidt-Cassegrain, Sky-Watcher EQ6 mount.
NGC 891
TONY FuNNELL, SuSSEx, NOvEMbER 2013
Tony says: “This is a very popular galaxy that appears as a really dim line visually but develops great detail when it is imaged with a CCD camera.”
Equipment: Atik 314 CCD camera, 8-inch Ritchey-Chrétien telescope, Sky-Watcher EQ6 mount.
HOTSHOTS APRIL 29
skyatnightmagazine.com 2014
The leaping puma in the Rosette Nebula
kFIR SIMON, GAN-YAvNE, ISRAEL 18,30 AND 31 JANuARY 2014
kfr says: “I like this image because of all the dark nebulae in the lower part of the frame, which resemble a parade of animals.“
Equipment: SbIG ST8300M CCD camera, Altair Astro 8-inch Ritchey-Chrétien astrograph, ASA DDM 60 PRO direct drive mount.
Jupiter and Europa
TOM HOWARD, SuSSEx, 9 DECEMbER 2013
Tom says: “I have never been interested in the expense and extra effort required in using colour flters for imaging. This image showed me what can be achieved with a one-shot colour planetary camera under excellent seeing conditions.”
Equipment: Celestron Skyris 618C CCD camera, Celestron C11 Schmidt-Cassegrain, Sky-Watcher EQ6 mount.
NGC 891
TONY FuNNELL, SuSSEx, NOvEMbER 2013
Tony says: “This is a very popular galaxy that appears as a really dim line visually but develops great detail when it is imaged with a CCD camera.”
Equipment: Atik 314 CCD camera, 8-inch Ritchey-Chrétien telescope, Sky-Watcher EQ6 mount.
skyatnightmagazine.com 2014
30
The Milly Way and Venus
LuIS ARGERICH, ARGENTINA, 3 NOvEMbER 2013
Luis says: “Here’s a shot of the Milky Way at dusk with venus and the Moon just in the middle of it. Plenty of frefies decorate the scene. I like how the Milky Way can be seen though the sky is not fully dark.”
Equipment: Canon EOS 6D DSLR camera, 14mm lens.
IC 410, IC 405, IC 417 and NGC 1931
SARA WAGER, vALENCIA, SPAIN, NOvEMbER 2013 TO JANuARY 2014
Sara says: “This mosaic took me two months to complete. It represents a total of 152 30-minute exposures and an integration time of 76 hours. The Flaming Star Nebula, IC 405, is aptly showing as a bright orange fame. The four targets all nestle neatly in the frame.”
Equipment: Atik 460ExM CCD camera, Takahashi FSQ85 telescope, Avalon Linear Fast Reverse equatorial mount.
The Pleiades
TERRY HANCOCk AND RObERT FIELDS, MICHIGAN 13 NOvEMbER AND 28 DECEMbER 2013
Terry says: “Here is a collaborated image of the popular star cluster commonly known as the Seven Sisters. While we continue with awful weather here in Michigan it just makes sense to collaborate – this time using different telescopes and cameras, but with a similar feld of view.”
Equipment: QHY11S monochrome CCD camera, STL 11000 monochrome CCD camera, Takahashi Epsilon-180ED telescope, Takahashi FSQ-106 telescope, Paramount GT-1100S German equatorial mount, Astro-Physics AP900 German equatorial mount.
skyatnightmagazine.com 2014
30
The Milly Way and Venus
LuIS ARGERICH, ARGENTINA, 3 NOvEMbER 2013
Luis says: “Here’s a shot of the Milky Way at dusk with venus and the Moon just in the middle of it. Plenty of frefies decorate the scene. I like how the Milky Way can be seen though the sky is not fully dark.”
Equipment: Canon EOS 6D DSLR camera, 14mm lens.
IC 410, IC 405, IC 417 and NGC 1931
SARA WAGER, vALENCIA, SPAIN, NOvEMbER 2013 TO JANuARY 2014
Sara says: “This mosaic took me two months to complete. It represents a total of 152 30-minute exposures and an integration time of 76 hours. The Flaming Star Nebula, IC 405, is aptly showing as a bright orange fame. The four targets all nestle neatly in the frame.”
Equipment: Atik 460ExM CCD camera, Takahashi FSQ85 telescope, Avalon Linear Fast Reverse equatorial mount.
The Pleiades
TERRY HANCOCk AND RObERT FIELDS, MICHIGAN 13 NOvEMbER AND 28 DECEMbER 2013
Terry says: “Here is a collaborated image of the popular star cluster commonly known as the Seven Sisters. While we continue with awful weather here in Michigan it just makes sense to collaborate – this time using different telescopes and cameras, but with a similar feld of view.”
Equipment: QHY11S monochrome CCD camera, STL 11000 monochrome CCD camera, Takahashi Epsilon-180ED telescope, Takahashi FSQ-106 telescope, Paramount GT-1100S German equatorial mount, Astro-Physics AP900 German equatorial mount.
HOTSHOTS APRIL 31
skyatnightmagazine.com 2014
NGC 6231
HAREL bOREN, NAMIbIA, JuNE 2011
Harel says: “Here’s an image, shot from the kalahari Desert in June 2011, which I have fnally come around to processing. It captures a colourful star feld comprising open cluster NGC 6231 through to the Prawn Nebula.”
Equipment: SbIG ST8300M CCD camera, Newtonian refector, Astro-Physics 1200GTO mount.
Earthshine
RICHARD bAILEY, bRAuNSTON, DECEMbER 2013
Richard says: “I managed to capture this image of earthshine just before the Moon set behind a tree. It was bright and the earthshine really stood out.”
Equipment: Canon EOS 1000D DSLR camera, 80ED refractor.
Sharpless 234 and 237
DAN CROWSON, MISSOuRI, 4 NOvEMbER 2013
Dan says: “Sharpless 234 and 237 are fairly bright emission nebulae located approximately 6,800 lightyears away in Auriga. Sharpless 234 is the nebula near the centre of the image; the cluster of stars is designated as Stock 8. Sharpless 237 is the smaller nebula on the left side of the image. It surrounds open cluster NGC 1931.”
Equipment: Atik 383L+ mono CCD camera, APM 80/470 apo refractor, Sky-Watcher NEQ6 mount.
HOTSHOTS APRIL 31
skyatnightmagazine.com 2014
NGC 6231
HAREL bOREN, NAMIbIA, JuNE 2011
Harel says: “Here’s an image, shot from the kalahari Desert in June 2011, which I have fnally come around to processing. It captures a colourful star feld comprising open cluster NGC 6231 through to the Prawn Nebula.”
Equipment: SbIG ST8300M CCD camera, Newtonian refector, Astro-Physics 1200GTO mount.
Earthshine
RICHARD bAILEY, bRAuNSTON, DECEMbER 2013
Richard says: “I managed to capture this image of earthshine just before the Moon set behind a tree. It was bright and the earthshine really stood out.”
Equipment: Canon EOS 1000D DSLR camera, 80ED refractor.
Sharpless 234 and 237
DAN CROWSON, MISSOuRI, 4 NOvEMbER 2013
Dan says: “Sharpless 234 and 237 are fairly bright emission nebulae located approximately 6,800 lightyears away in Auriga. Sharpless 234 is the nebula near the centre of the image; the cluster of stars is designated as Stock 8. Sharpless 237 is the smaller nebula on the left side of the image. It surrounds open cluster NGC 1931.”
Equipment: Atik 383L+ mono CCD camera, APM 80/470 apo refractor, Sky-Watcher NEQ6 mount.
ENTER TO WIN A PRIzE!
We’ve teamed up with the Widescreen Centre to offer the winner of next month’s best Hotshots image a fantastic prize. The winner will receive an Orion StarShoot Solar System Colour Imager Iv camera, designed for capturing sharp shots of the Moon and planets.
www.widescreen-centre.co.uk • 020 7935 2580
Email your pictures to us at hotshots@skyatnightmagazine.com or enter online. £99WORTH
skyatnightmagazine.com 2014
32 HOTSHOTS APRIL
The Andromeda Galaxy
GARY ANDERSON, GALLOWAY, 1 NOvEMbER 2013
Gary says: “This is my best image of M31 to date as I always fnd processing galaxies diffcult. The detail in the dust lanes is clear and the core is not blown out, giving a nice natural look.”
Equipment: Canon EOS 1000D DSLR camera, Sky-Watcher 80ED telescope.
The Flame and Horsehead Nebulae
PAuL GORDON, ESSEx, 5 JANuARY 2014
Paul says: “This image is the result of 12 fve-minute exposures at ISO 800.”
Equipment: Canon EOS 1000D DSLR camera, William Optics ZS80 telescope.
The Iris Nebula
MARk GRIFFITH SWINDON 4 DECEMbER 2013
Mark says: “This was one of the frst deep-sky objects I ever tried to image – with poor results, far too diffcult for a beginner! This is my best image of this nebula yet.”
Equipment: Atik 383L+ CCD camera, 8-inch Ritchey-Chrétien telescope, Sky-Watcher NEQ6 PRO mount.
ENTER TO WIN A PRIzE!
We’ve teamed up with the Widescreen Centre to offer the winner of next month’s best Hotshots image a fantastic prize. The winner will receive an Orion StarShoot Solar System Colour Imager Iv camera, designed for capturing sharp shots of the Moon and planets.
www.widescreen-centre.co.uk • 020 7935 2580
Email your pictures to us at hotshots@skyatnightmagazine.com or enter online. £99WORTH
skyatnightmagazine.com 2014
32 HOTSHOTS APRIL
The Andromeda Galaxy
GARY ANDERSON, GALLOWAY, 1 NOvEMbER 2013
Gary says: “This is my best image of M31 to date as I always fnd processing galaxies diffcult. The detail in the dust lanes is clear and the core is not blown out, giving a nice natural look.”
Equipment: Canon EOS 1000D DSLR camera, Sky-Watcher 80ED telescope.
The Flame and Horsehead Nebulae
PAuL GORDON, ESSEx, 5 JANuARY 2014
Paul says: “This image is the result of 12 fve-minute exposures at ISO 800.”
Equipment: Canon EOS 1000D DSLR camera, William Optics ZS80 telescope.
The Iris Nebula
MARk GRIFFITH SWINDON 4 DECEMbER 2013
Mark says: “This was one of the frst deep-sky objects I ever tried to image – with poor results, far too diffcult for a beginner! This is my best image of this nebula yet.”
Equipment: Atik 383L+ CCD camera, 8-inch Ritchey-Chrétien telescope, Sky-Watcher NEQ6 PRO mount.
It’s a planetary murder mystery: how did the once-wet Mars end up the dusty world it is today Sean Blair asks if we’re any closer to an answer
It’s a planetary murder mystery: how did the once-wet Mars end up the dusty world it is today Sean Blair asks if we’re any closer to an answer
NA
SA
/JPL
-CA
LteC
h/C
orN
eLL/
Ariz
oN
A S
tAte
UN
iv,
NA
SA
/JPL
/te
xA
S A
&M
/C
orN
eLL
On 8 April, Mars comes to its
closest point to Earth in its
two-year orbit. Observing
that bright red world holds an
added excitement, as we are looking at a
planet we feel we know intimately. For years,
Martian rovers have transmitted back
views of a place remarkably like home, with
morning mists and blue-tinted sunsets.
It’s a beguiling illusion. If anyone were
to step onto the surface unprotected, the
thin atmosphere would cause the saliva
to boil away from their lips before they
blacked out. Even if they managed to
shout for help, they would be inaudible
from a distance of a few tens of metres.
Never forget Mars is an alien world
– its single most alien element being
the ghostly remnant of an atmosphere.
Surface air pressure is less than one
hundredth that of Earth’s at sea level,
equivalent to an altitude of 35km on our
planet, or three times higher than the
cruising height of a commercial airliner.
If there were suffcient concentrations to
breathe, the air would be poisonous: more
than 95 per cent carbon dioxide, plus
nitrogen, argon and other trace gases.
In 1946, astronomer Gerard Kuiper
identifed carbon dioxide as Mars’s major
atmospheric constituent. Previously it
was assumed Mars had an Earth-like
atmosphere, because of the ‘clouds’ so
frequently sighted, as well as a stubborn
belief in the ‘canals’ that Percival Lowell
– he who founded the Lowell Observatory
in Arizona – was believed to have
observed on the planet’s surface.
Scant remainsInto the 1960s, ground-based spectrographic
observations suggested that the Martian
atmosphere was extremely scant,
something confrmed by radio science
experiments during Mariner 4’s two-
day fyby of the planet in July 1965. That
mission, followed by Mariner 6 and 7
in 1969, charted a cratered Moon-like
world. But a fuller picture was given
in January 1972, from Mariner 9. The
spacecraft actually attained Mars orbit the
previous November, but its observations
were delayed by a planet-wide dust
storm – the
Though the blue-tinted sunsets look homely, conditions on Mars are anything but
It looks desolate now, but the evidence indicates that Mars
was once much more pleasant
>
NA
SA
/JPL
-CA
LteC
h/C
orN
eLL/
Ariz
oN
A S
tAte
UN
iv,
NA
SA
/JPL
/te
xA
S A
&M
/C
orN
eLL
On 8 April, Mars comes to its
closest point to Earth in its
two-year orbit. Observing
that bright red world holds an
added excitement, as we are looking at a
planet we feel we know intimately. For years,
Martian rovers have transmitted back
views of a place remarkably like home, with
morning mists and blue-tinted sunsets.
It’s a beguiling illusion. If anyone were
to step onto the surface unprotected, the
thin atmosphere would cause the saliva
to boil away from their lips before they
blacked out. Even if they managed to
shout for help, they would be inaudible
from a distance of a few tens of metres.
Never forget Mars is an alien world
– its single most alien element being
the ghostly remnant of an atmosphere.
Surface air pressure is less than one
hundredth that of Earth’s at sea level,
equivalent to an altitude of 35km on our
planet, or three times higher than the
cruising height of a commercial airliner.
If there were suffcient concentrations to
breathe, the air would be poisonous: more
than 95 per cent carbon dioxide, plus
nitrogen, argon and other trace gases.
In 1946, astronomer Gerard Kuiper
identifed carbon dioxide as Mars’s major
atmospheric constituent. Previously it
was assumed Mars had an Earth-like
atmosphere, because of the ‘clouds’ so
frequently sighted, as well as a stubborn
belief in the ‘canals’ that Percival Lowell
– he who founded the Lowell Observatory
in Arizona – was believed to have
observed on the planet’s surface.
Scant remainsInto the 1960s, ground-based spectrographic
observations suggested that the Martian
atmosphere was extremely scant,
something confrmed by radio science
experiments during Mariner 4’s two-
day fyby of the planet in July 1965. That
mission, followed by Mariner 6 and 7
in 1969, charted a cratered Moon-like
world. But a fuller picture was given
in January 1972, from Mariner 9. The
spacecraft actually attained Mars orbit the
previous November, but its observations
were delayed by a planet-wide dust
storm – the
Though the blue-tinted sunsets look homely, conditions on Mars are anything but
It looks desolate now, but the evidence indicates that Mars
was once much more pleasant
>
36
skyatnightmagazine.com 2014
Kee
S v
eeN
eNBo
S/SC
ieN
Ce
Pho
to L
iBr
ArY
, N
ASA
/JPL
-CA
LteC
h x
3,
NA
SA
, N
ASA
/JA
MeS
BeL
L (C
orN
eLL
UN
iv.)/M
iCh
AeL
Wo
Lff
(SPA
Ce
SC
ieN
Ce
iNSt.
) A
Nd
th
e h
UBBLe
her
itA
ge
teA
M (
StS
Ci/
AU
rA
), S
tev
e Le
e (U
Niv
erSit
Y o
f C
oLo
rA
do
)/Ji
M B
eLL
(Co
rN
eLL
UN
iver
Sit
Y)/
MiK
e W
oLf
f (S
PAC
e SC
ieN
Ce
iNSti
tUte
) A
Nd
NA
SA
, N
ASA
/g
od
dA
rd
true nature of the ‘clouds’. Once the dust settled,
Mariner 9 revealed a startlingly Earth-like world,
with layered ice caps, cirrus clouds, and dried-up
food plains and riverbeds.
Around four billion years ago, Mars’s atmosphere
was still dense enough to sustain liquid water on
the surface – the atmosphere was probably denser
than Earth’s, because it receives only less than half
the energy from the Sun as Earth does, and the Sun
shone 30 per cent less brightly at the time. So Mars
exploration became a kind of murder mystery: why
did this initially hospitable planet perish? How was
its atmosphere stolen away?
The 1976 Viking missions flled in details of
the murder scene – including in-situ atmospheric
measurements, though Viking researchers were
themselves beguiled by Mars’s Earth-like appearance.
The thin sky was graded blue in initial lander
images, but calibration checks confrmed airborne
dust actually left it reddish.
Fast forward to today and two new robotic
detectives are en route to join the rovers and
orbiters already at Mars. India’s Mangalyaan,
offcially the Mars Orbiter Mission (MOM), weighs
in at more than a tonne including fuel, although
only 15kg of that mass is scientifc payload. There
are fve instruments aboard, including two focused
on the detection of trace gases deuterium and
methane. But for the new space-faring nation of
India, MOM’s major achievement would simply be
achieving Mars orbital insertion, which is scheduled
for September. Any useful science would be a bonus.
The plot thickensHopes are higher for NASA’s MAVEN (Mars
Atmosphere and Volatile Evolution), also due
to reach the Red Planet in September. This van-
sized spacecraft will focus on particles escaping
from Mars right now, not just by monitoring
the upper atmosphere, but actually descending
into it once per orbit.
“We’re applying previous experience of
aerobraking spacecraft to go down as low as 150km,
which is below the altitude that escape occurs,” says
Bruce Javovsky, MAVEN’s principal investigator.
“Then we’ll be performing fve ‘deep dips’ during
our year-long mission where we go even lower, to
125km, to sample the entire stratifed column of
the upper atmosphere. The Martian atmosphere
is tenuous enough that we aren’t in danger, but
some high-power instruments will be switched
off to avoid damage. Our gull-design solar
wings help ensure aerodynamic stability.
Þ Today we see dried-up lakes; 3.5 billion years ago, we may have seen something more like this
þ Mariner 9, the frst craft to enter Martian orbit, revealed a slew of Earth-like surface features
>
36
skyatnightmagazine.com 2014
Kee
S v
eeN
eNBo
S/SC
ieN
Ce
Pho
to L
iBr
ArY
, N
ASA
/JPL
-CA
LteC
h x
3,
NA
SA
, N
ASA
/JA
MeS
BeL
L (C
orN
eLL
UN
iv.)/M
iCh
AeL
Wo
Lff
(SPA
Ce
SC
ieN
Ce
iNSt.
) A
Nd
th
e h
UBBLe
her
itA
ge
teA
M (
StS
Ci/
AU
rA
), S
tev
e Le
e (U
Niv
erSit
Y o
f C
oLo
rA
do
)/Ji
M B
eLL
(Co
rN
eLL
UN
iver
Sit
Y)/
MiK
e W
oLf
f (S
PAC
e SC
ieN
Ce
iNSti
tUte
) A
Nd
NA
SA
, N
ASA
/g
od
dA
rd
true nature of the ‘clouds’. Once the dust settled,
Mariner 9 revealed a startlingly Earth-like world,
with layered ice caps, cirrus clouds, and dried-up
food plains and riverbeds.
Around four billion years ago, Mars’s atmosphere
was still dense enough to sustain liquid water on
the surface – the atmosphere was probably denser
than Earth’s, because it receives only less than half
the energy from the Sun as Earth does, and the Sun
shone 30 per cent less brightly at the time. So Mars
exploration became a kind of murder mystery: why
did this initially hospitable planet perish? How was
its atmosphere stolen away?
The 1976 Viking missions flled in details of
the murder scene – including in-situ atmospheric
measurements, though Viking researchers were
themselves beguiled by Mars’s Earth-like appearance.
The thin sky was graded blue in initial lander
images, but calibration checks confrmed airborne
dust actually left it reddish.
Fast forward to today and two new robotic
detectives are en route to join the rovers and
orbiters already at Mars. India’s Mangalyaan,
offcially the Mars Orbiter Mission (MOM), weighs
in at more than a tonne including fuel, although
only 15kg of that mass is scientifc payload. There
are fve instruments aboard, including two focused
on the detection of trace gases deuterium and
methane. But for the new space-faring nation of
India, MOM’s major achievement would simply be
achieving Mars orbital insertion, which is scheduled
for September. Any useful science would be a bonus.
The plot thickensHopes are higher for NASA’s MAVEN (Mars
Atmosphere and Volatile Evolution), also due
to reach the Red Planet in September. This van-
sized spacecraft will focus on particles escaping
from Mars right now, not just by monitoring
the upper atmosphere, but actually descending
into it once per orbit.
“We’re applying previous experience of
aerobraking spacecraft to go down as low as 150km,
which is below the altitude that escape occurs,” says
Bruce Javovsky, MAVEN’s principal investigator.
“Then we’ll be performing fve ‘deep dips’ during
our year-long mission where we go even lower, to
125km, to sample the entire stratifed column of
the upper atmosphere. The Martian atmosphere
is tenuous enough that we aren’t in danger, but
some high-power instruments will be switched
off to avoid damage. Our gull-design solar
wings help ensure aerodynamic stability.
Þ Today we see dried-up lakes; 3.5 billion years ago, we may have seen something more like this
þ Mariner 9, the frst craft to enter Martian orbit, revealed a slew of Earth-like surface features
>
mars’s atmosphere april 37
skyatnightmagazine.com 2014
seasonal Changes
Giant dust stormsIt is when Mars draws closest to the Sun that the greatest planetary-scale dust storms occur. Mars’s wispy atmosphere is unable to transfer heat effciently, causing regional temperature differences of up to 30°C to drive winds above 100km/h, lifting thin dust that blankets whole regions or the entire planet. Summer dust devils are also common. Any astronaut would feel only a mild breeze, although dust storms might also generate worrying static electric ‘e-felds’.
“What we want to understand are the processes
occurring in the upper atmosphere today. What is
its composition and loss rate? How is this affected
by incoming solar energy rates?”
MAVEN will build on the atmospheric
observations of ESA’s Mars Express, which has
been in orbit around Mars for a decade, sampling
current atmospheric loss rates. The ESA probe
identifed Mars’s unique equatorial aurora, a result
of solar wind particles encountering the magnetised
remnants of the planet’s now-lost magnetic feld.
These cause ultraviolet glows that are sadly invisible
to human eyes.
The missing magnetic feld is the frst suspect in
the murder mystery. It’s a symptom of Mars’s small
stature: only half Earth’s size and only 11 per cent
Mars has terrestrial-style seasons, encouraged by its Earth-like axial tilt. Its highly eccentric (very ‘uncircular’) orbit means its distance from the Sun varies over the course of a 687-day Martian year by some 42 million km
shiftinG ice capsMars’s two polar caps undergo dramatic seasonal shifts. During the darkness of winter atmospheric carbon dioxide freezes out of the air, falling as snow. The effect is greatest when Mars is farthest from the Sun; atmospheric pressure drops by a third. The seasonal southern cap is larger (extending more than halfway to the equator) because the Martian seasons are uneven: the southern winter lasts longer, coinciding with Mars’s aphelion, its maximum distance from the Sun. The southern summer is correspondingly short, but also warmer, with 40 per cent more sunlight. This means much of the south pole’s 1km-thick carbon dioxide layer is vaporised, leaving a 3km-thick pole of water ice behind.
equatorial streaksThe sharp-eyed Mars Reconnaissance Orbiter has spotted surface streaks around equatorial territory. Extending downhill, these dark streaks appear at the warmest time of year, fading as the planet grows cooler, only to return the following summer. Flowing liquid water is the most likely explanation, probably originating from buried permafrost with salt deposits acting as a kind of antifreeze. This 2013 discovery builds on earlier fnds of apparent freshly formed gullies down craters and slopes.
MAVEN’s bird-like ‘gull wings’ will help it swoop low over the Martian surface
>
JUNE
2001
SEptEMbEr
2001
mars’s atmosphere april 37
skyatnightmagazine.com 2014
seasonal Changes
Giant dust stormsIt is when Mars draws closest to the Sun that the greatest planetary-scale dust storms occur. Mars’s wispy atmosphere is unable to transfer heat effciently, causing regional temperature differences of up to 30°C to drive winds above 100km/h, lifting thin dust that blankets whole regions or the entire planet. Summer dust devils are also common. Any astronaut would feel only a mild breeze, although dust storms might also generate worrying static electric ‘e-felds’.
“What we want to understand are the processes
occurring in the upper atmosphere today. What is
its composition and loss rate? How is this affected
by incoming solar energy rates?”
MAVEN will build on the atmospheric
observations of ESA’s Mars Express, which has
been in orbit around Mars for a decade, sampling
current atmospheric loss rates. The ESA probe
identifed Mars’s unique equatorial aurora, a result
of solar wind particles encountering the magnetised
remnants of the planet’s now-lost magnetic feld.
These cause ultraviolet glows that are sadly invisible
to human eyes.
The missing magnetic feld is the frst suspect in
the murder mystery. It’s a symptom of Mars’s small
stature: only half Earth’s size and only 11 per cent
Mars has terrestrial-style seasons, encouraged by its Earth-like axial tilt. Its highly eccentric (very ‘uncircular’) orbit means its distance from the Sun varies over the course of a 687-day Martian year by some 42 million km
shiftinG ice capsMars’s two polar caps undergo dramatic seasonal shifts. During the darkness of winter atmospheric carbon dioxide freezes out of the air, falling as snow. The effect is greatest when Mars is farthest from the Sun; atmospheric pressure drops by a third. The seasonal southern cap is larger (extending more than halfway to the equator) because the Martian seasons are uneven: the southern winter lasts longer, coinciding with Mars’s aphelion, its maximum distance from the Sun. The southern summer is correspondingly short, but also warmer, with 40 per cent more sunlight. This means much of the south pole’s 1km-thick carbon dioxide layer is vaporised, leaving a 3km-thick pole of water ice behind.
equatorial streaksThe sharp-eyed Mars Reconnaissance Orbiter has spotted surface streaks around equatorial territory. Extending downhill, these dark streaks appear at the warmest time of year, fading as the planet grows cooler, only to return the following summer. Flowing liquid water is the most likely explanation, probably originating from buried permafrost with salt deposits acting as a kind of antifreeze. This 2013 discovery builds on earlier fnds of apparent freshly formed gullies down craters and slopes.
MAVEN’s bird-like ‘gull wings’ will help it swoop low over the Martian surface
>
JUNE
2001
SEptEMbEr
2001
38
skyatnightmagazine.com 2014
its mass with about 38 per cent terrestrial gravity.
Mars’s smaller molten core would have cooled
rapidly, shutting down its protective magnetic feld.
At high altitude, gases are split apart by ultraviolet
radiation into electrically charged ions, which are
then accelerated to escape velocity by the solar
wind. Like a slow-motion comet, Mars’s atmosphere
is being very gradually blown away. The snag is that
Mars Express suggests that escape susceptibility is
limited to lightweight atoms such as hydrogen or
oxygen ions – not heavier carbon dioxide, which has
always formed most of the atmosphere.
Suspect two is the possibility that early Mars’s
warm wetness sparked its doom. Carbon was
steadily extracted from the atmosphere by damp
silicate rocks to form solid carbonates. Earth is
only saved a similar fate by plate tectonics regularly
recycling the surface to liberate stored carbon back
into the atmosphere– but, again, Mars is too small
for plate tectonics to take hold. The problem here
is that the vast amount of carbonate deposits this
implies has still to be found.
Suspect three is suggested by the planet’s heavily
cratered surface – and the event due to happen this
October. Heading towards us at 56km/s, Comet
C/2013 A1 Siding Spring is projected to pass within
41,300km of Mars. Both MAVEN and Mars Express
will have their orbits altered to shelter them behind
Mars during closest approach – fearing cometary
dust impacts. They will use their high-gain antennas
as shields and angle their solar arrays edge-on.
Such close encounters are rare today, but as late
as 3.8 billion years ago the Solar System remained
a violent neighbourhood. The Martian atmosphere
might have been expelled to space by repeated
impacts, also triggering catastrophic foods by
temporarily melting permafrost.
The methane mysteryHow lively is today’s Martian atmosphere?
Memorably, James Lovelock came up with his
Gaia theory after contrasting Earth’s life-driven
atmosphere with static Mars. But how static is it
really? In 2004 both Mars Express and ground-
based observatories detected short-lived plumes
of methane over various Martian regions. The
discovery remains hugely controversial – on Earth
it takes hundreds of years for photochemistry to
remove methane from the atmosphere. Then last
year NASA’s Curiosity rover failed to detect any
Mars methane whatsoever, although terrestrial
spectrographic monitoring goes on.
“Most of the time we don’t detect anything; it’s
only released spasmodically,” says Michael Mumma
of the Solar System Exploration Division at NASA’s
The hunT for methaneThe methane sensor on India’s Mars Orbiter Mission (MOM) aims to solve a decade-long scientifc mystery. It will be put into action as MOM rises to its farthest distance from Mars, around 80,000km – at this distance MOM will move relatively slowly compared to Mars below, allowing for long-exposure searches for the spectral fngerprints of this colourless, odourless gas.
In 2004, Mars Express and ground-based observatories detected small amounts of methane gas on Mars, averaging 10 parts per billion but rising as high as 30 at times (by comparison, Earth’s atmosphere contains 1,800 parts per billion). It was an exciting discovery because terrestrial
methane originates mainly from biological processes, or else volcanoes. But last year NASA’s Curiosity rover analysed local air samples, failing to fnd any methane at all.
Had the methane never been there at all, or is some unknown phenomenon removing it from the atmosphere at a rate hundreds of times faster than terrestrial methane? Proposed mechanisms include dust storm ‘electric felds’, soil superoxides and methane-eating bacteria. Hopefully, MOM will help fnd the answer; if not, Europe’s ExoMars Trace Gas Orbiter – due for launch in 2016 and possessing parts per trillion sensitivity, should be able to do so.
MEthaNE rElEaSE: NorthErN SUMMEr 2003
Methane concentration (parts per billion)
0 5 10 15 20 25 30
Data published in 2009 revealed localised methane,
possibly from an active source
MOM, launched in November 2013, will look for methane spectrally
NA
SA
/JPL
-CA
LteC
h, N
ASA
/tr
eN
t SC
hiN
dLe
r, iN
diA
SPA
Ce
reS
eA
rC
h o
rg
AN
iSA
tio
N,
NA
SA
/JPL
-CA
LteC
h/C
orN
eLL
UN
iver
Sit
Y, N
ASA
/JPL
/M
SSS,
eSA
–d
. d
UC
ro
S
>
38
skyatnightmagazine.com 2014
its mass with about 38 per cent terrestrial gravity.
Mars’s smaller molten core would have cooled
rapidly, shutting down its protective magnetic feld.
At high altitude, gases are split apart by ultraviolet
radiation into electrically charged ions, which are
then accelerated to escape velocity by the solar
wind. Like a slow-motion comet, Mars’s atmosphere
is being very gradually blown away. The snag is that
Mars Express suggests that escape susceptibility is
limited to lightweight atoms such as hydrogen or
oxygen ions – not heavier carbon dioxide, which has
always formed most of the atmosphere.
Suspect two is the possibility that early Mars’s
warm wetness sparked its doom. Carbon was
steadily extracted from the atmosphere by damp
silicate rocks to form solid carbonates. Earth is
only saved a similar fate by plate tectonics regularly
recycling the surface to liberate stored carbon back
into the atmosphere– but, again, Mars is too small
for plate tectonics to take hold. The problem here
is that the vast amount of carbonate deposits this
implies has still to be found.
Suspect three is suggested by the planet’s heavily
cratered surface – and the event due to happen this
October. Heading towards us at 56km/s, Comet
C/2013 A1 Siding Spring is projected to pass within
41,300km of Mars. Both MAVEN and Mars Express
will have their orbits altered to shelter them behind
Mars during closest approach – fearing cometary
dust impacts. They will use their high-gain antennas
as shields and angle their solar arrays edge-on.
Such close encounters are rare today, but as late
as 3.8 billion years ago the Solar System remained
a violent neighbourhood. The Martian atmosphere
might have been expelled to space by repeated
impacts, also triggering catastrophic foods by
temporarily melting permafrost.
The methane mysteryHow lively is today’s Martian atmosphere?
Memorably, James Lovelock came up with his
Gaia theory after contrasting Earth’s life-driven
atmosphere with static Mars. But how static is it
really? In 2004 both Mars Express and ground-
based observatories detected short-lived plumes
of methane over various Martian regions. The
discovery remains hugely controversial – on Earth
it takes hundreds of years for photochemistry to
remove methane from the atmosphere. Then last
year NASA’s Curiosity rover failed to detect any
Mars methane whatsoever, although terrestrial
spectrographic monitoring goes on.
“Most of the time we don’t detect anything; it’s
only released spasmodically,” says Michael Mumma
of the Solar System Exploration Division at NASA’s
The hunT for methaneThe methane sensor on India’s Mars Orbiter Mission (MOM) aims to solve a decade-long scientifc mystery. It will be put into action as MOM rises to its farthest distance from Mars, around 80,000km – at this distance MOM will move relatively slowly compared to Mars below, allowing for long-exposure searches for the spectral fngerprints of this colourless, odourless gas.
In 2004, Mars Express and ground-based observatories detected small amounts of methane gas on Mars, averaging 10 parts per billion but rising as high as 30 at times (by comparison, Earth’s atmosphere contains 1,800 parts per billion). It was an exciting discovery because terrestrial
methane originates mainly from biological processes, or else volcanoes. But last year NASA’s Curiosity rover analysed local air samples, failing to fnd any methane at all.
Had the methane never been there at all, or is some unknown phenomenon removing it from the atmosphere at a rate hundreds of times faster than terrestrial methane? Proposed mechanisms include dust storm ‘electric felds’, soil superoxides and methane-eating bacteria. Hopefully, MOM will help fnd the answer; if not, Europe’s ExoMars Trace Gas Orbiter – due for launch in 2016 and possessing parts per trillion sensitivity, should be able to do so.
MEthaNE rElEaSE: NorthErN SUMMEr 2003
Methane concentration (parts per billion)
0 5 10 15 20 25 30
Data published in 2009 revealed localised methane,
possibly from an active source
MOM, launched in November 2013, will look for methane spectrally
NA
SA
/JPL
-CA
LteC
h,
NA
SA
/tr
eN
t SC
hiN
dLe
r,
iNd
iA S
PAC
e reS
eA
rC
h o
rg
AN
iSA
tio
N,
NA
SA
/JPL
-CA
LteC
h/C
orN
eLL
UN
iver
Sit
Y, N
ASA
/JPL
/M
SSS,
eSA
–d
. d
UC
ro
S
>
mars’s atmosphere april 39
skyatnightmagazine.com 2014
ABOUT THE WRITER
Sean Blair is a science and technology journalist. A former guinness World records researcher, he now edits eSA’s space engineering website.
sporadic plumes compared to past seasonal
averages. And a new ESA mission, the
ExoMars Trace Gas Orbiter, joins the
search in 2016. It will also measure
broader trace gas isotope ratios
to gain insight into the
atmosphere’s past
rates of change.
“This 2016 mission
should give us some pretty
defnitive information,” says
Mumma. “What we don’t have
yet is an additional destruction
mechanism for the methane to be
disappearing, but there’s much we
don’t know about Mars and that’s
why we continue to send spacecraft
there. It’s an exciting time; within a
decade we should have an answer.”
Þ The ExoMars orbiter will look for clues on how fast Mars’s atmosphere has altered over time
water on mars
The number of times mainstream headline writers have hailed the discovery of ‘Water on Mars!’ must be well into double digits by now. We’ve known Martian water once existed since 1969, when Mariner 9 charted drainage channels – apparent evidence of a warm, wet early Mars. The mystery of these features is that they appear quite abruptly in the landscape, rather than by the gradual accumulation of river systems. These might have been comparatively brief-lived phenomena, based on transitory meltwater from geological activity or meteorite impacts.
The 1970s Viking landers recorded early morning water-ice mist and frost – although coatings are only a fraction of a millimetre thick – while their orbital
counterparts confrmed trace levels of atmospheric water vapour. More recently, Mars Express has shown water vapour can be ‘supersaturated’ when Mars is at its coldest,
making it wetter than previously thought (although still with 10,000 times
less water vapour than Earth). Looking at the ground, radar instruments proved
that the Martian poles contain enough water ice to food the entire surface to a depth of 11m and established that subsurface ice extends down to mid- latitudes. This ice has
been seen directly by the Mars Reconnaissance
Orbiter, following asteroid impacts uncovering the
bright-white of water ice, which eventually fades. Mapping has also
demonstrated Mars’s northern lowlands are suffciently fat to have formed a shallow ocean.
NASA’s rovers have gathered in-situ evidence: Opportunity discovered haematite ‘blueberries’
that can only be formed in water, suggesting the equatorial Meridian Planum plain was once hot springs or even an acid-tinged lake. Last year Curiosity went one better, establishing through streambed clay deposits that 3.5 billion years ago Gale Crater housed a lake with water ‘good enough to drink’.
Spare a thought also for the oft-neglected 2008 Mars Phoenix lander. Although it was immobile, its thrusters cleared dust to reveal bright water ice beneath, and apparent liquid droplets were recorded fowing along its landing struts – potentially the historic frst detection of liquid Martian water – kept from freezing by perchlorate salts.
Goddard Space Flight Center. “We have
campaigns at three observatories – ESO’s
Very Large Telescope in Chile, Keck
and NASA’s Infrared Telescope, both
in Hawaii. Adaptive optics provide
high angular resolution no
matter the distance. The real
issue is we require a large
Doppler shift to take the Mars
spectral lines away from
Earth’s lines. So we observe at
times when Mars has a high
line of sight velocity relative to
Earth – in January it was moving
towards Earth at about 17 km/s
– leaving us confdent we’re not
mistaking terrestrial methane.
“We’re also looking for deuterium,
a heavy isotope of water. If subsurface
methane is being released seasonally by
permafrost melting, then ancient water vapour
might escape too. This would possess a much
lower deuterium-water ratio than surface water
subject to atmospheric escape of lighter isotopes.
And water is much easier to detect than methane.”
Mars Express is meanwhile commencing
localised methane searches to try and catch
Þ Haematite ‘blueberries’ could only have formed in water, providing more evidence
Þ Meteorite impacts revealed hidden deposits
of water ice
S
mars’s atmosphere april 39
skyatnightmagazine.com 2014
ABOUT THE WRITER
Sean Blair is a science and technology journalist. A former guinness World records researcher, he now edits eSA’s space engineering website.
sporadic plumes compared to past seasonal
averages. And a new ESA mission, the
ExoMars Trace Gas Orbiter, joins the
search in 2016. It will also measure
broader trace gas isotope ratios
to gain insight into the
atmosphere’s past
rates of change.
“This 2016 mission
should give us some pretty
defnitive information,” says
Mumma. “What we don’t have
yet is an additional destruction
mechanism for the methane to be
disappearing, but there’s much we
don’t know about Mars and that’s
why we continue to send spacecraft
there. It’s an exciting time; within a
decade we should have an answer.”
Þ The ExoMars orbiter will look for clues on how fast Mars’s atmosphere has altered over time
water on mars
The number of times mainstream headline writers have hailed the discovery of ‘Water on Mars!’ must be well into double digits by now. We’ve known Martian water once existed since 1969, when Mariner 9 charted drainage channels – apparent evidence of a warm, wet early Mars. The mystery of these features is that they appear quite abruptly in the landscape, rather than by the gradual accumulation of river systems. These might have been comparatively brief-lived phenomena, based on transitory meltwater from geological activity or meteorite impacts.
The 1970s Viking landers recorded early morning water-ice mist and frost – although coatings are only a fraction of a millimetre thick – while their orbital
counterparts confrmed trace levels of atmospheric water vapour. More recently, Mars Express has shown water vapour can be ‘supersaturated’ when Mars is at its coldest,
making it wetter than previously thought (although still with 10,000 times
less water vapour than Earth). Looking at the ground, radar instruments proved
that the Martian poles contain enough water ice to food the entire surface to a depth of 11m and established that subsurface ice extends down to mid- latitudes. This ice has
been seen directly by the Mars Reconnaissance
Orbiter, following asteroid impacts uncovering the
bright-white of water ice, which eventually fades. Mapping has also
demonstrated Mars’s northern lowlands are suffciently fat to have formed a shallow ocean.
NASA’s rovers have gathered in-situ evidence: Opportunity discovered haematite ‘blueberries’
that can only be formed in water, suggesting the equatorial Meridian Planum plain was once hot springs or even an acid-tinged lake. Last year Curiosity went one better, establishing through streambed clay deposits that 3.5 billion years ago Gale Crater housed a lake with water ‘good enough to drink’.
Spare a thought also for the oft-neglected 2008 Mars Phoenix lander. Although it was immobile, its thrusters cleared dust to reveal bright water ice beneath, and apparent liquid droplets were recorded fowing along its landing struts – potentially the historic frst detection of liquid Martian water – kept from freezing by perchlorate salts.
Goddard Space Flight Center. “We have
campaigns at three observatories – ESO’s
Very Large Telescope in Chile, Keck
and NASA’s Infrared Telescope, both
in Hawaii. Adaptive optics provide
high angular resolution no
matter the distance. The real
issue is we require a large
Doppler shift to take the Mars
spectral lines away from
Earth’s lines. So we observe at
times when Mars has a high
line of sight velocity relative to
Earth – in January it was moving
towards Earth at about 17 km/s
– leaving us confdent we’re not
mistaking terrestrial methane.
“We’re also looking for deuterium,
a heavy isotope of water. If subsurface
methane is being released seasonally by
permafrost melting, then ancient water vapour
might escape too. This would possess a much
lower deuterium-water ratio than surface water
subject to atmospheric escape of lighter isotopes.
And water is much easier to detect than methane.”
Mars Express is meanwhile commencing
localised methane searches to try and catch
Þ Haematite ‘blueberries’ could only have formed in water, providing more evidence
Þ Meteorite impacts revealed hidden deposits
of water ice
S
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Ask your local dealer for the advanced solar
telescopes and filters of Lunt Solar Systems, or visit
our European homepage:
The next generation of solar filters and telescopes
H-alpha Telescopes and Filter
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White-Light Solar-PrismExclusive European Distributor - Optus GmbHE l i E Di ib O G bH
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Ask your local dealer for the advanced solar
telescopes and filters of Lunt Solar Systems, or visit
our European homepage:
The next generation of solar filters and telescopes
H-alpha Telescopes and Filter
Ca-K Filter
White-Light Solar-Prism
Mars is an alluring target because of how Earth-like many of its surface features are
th
ink
sto
ck Martin Lewis presents the ultimate guide to observing the Red Planet, its top sights, plus his imaging tips
Marsat oPPosition
Mars is an alluring target because of how Earth-like many of its surface features are
th
ink
sto
ck Martin Lewis presents the ultimate guide to observing the Red Planet, its top sights, plus his imaging tips
Marsat oPPosition
42
skyatnightmagazine.com 2014
Mars, that most captivating of planets,
visits our evening sky this spring,
reaching opposition in the constellation
of Virgo on 8 April. The Red Planet is
the only world in the Solar System that readily
reveals details of its rocky surface when viewed
from Earth and this, together with a multitude of
seasonal changes, makes it a fascinating planet to
observe. At opposition, when Mars is at its nearest,
it will shine as a ruddy beacon beckoning you to
view, but be warned, the Mars observing season is
relatively short. Once April is over, the planet appears
to shrink noticeably from week to week and by mid-
August it is all but lost, low in the evening twilight.
Around opposition, Mars will shine at mag.
–1.5, making it just as brilliant as the brightest
star in the night sky. The planet’s reddish colour
will be immediately apparent to the naked eye
and even more obvious in binoculars. Even at
opposition, however, it is unlikely you will see
any surface features in binoculars: for that you
will need a telescope.
When you look through the eyepiece of your
telescope what details on Mars might you be able to
see? The answer to this depends on the size of your
telescope and how steady your skies are, but also
on the planet’s apparent size and its height above
your horizon. Due to Mars’s noticeably elliptical
orbit, its size at opposition can vary by nearly a
factor of two. At its closest, Mars can be as large
as 25 arcseconds across, over half the apparent
diameter of the gas giant Jupiter. Unfortunately for
northern hemisphere observers, these very close
Mars oppositions always occur when the planet is
far south in the sky. Frustratingly for us in the
UK, this means that it then never gets particularly
high in our skies. A low altitude means the view
is much more affected by atmospheric turbulence
and this softens the view, blurring fne surface
detail, and stopping us making the most of
these close approaches.
The previous opposition in 2012 was certainly
not a close one. Mars was nearly at aphelion, its
farthest point from the Sun; at best the planet was
only 14 arcseconds across. However, to make up
for its small size, the planet was well north of the
celestial equator. This meant it was quite high in
our skies, helping us to see good surface details.
During this year’s opposition it will be larger, at
15.1 arcseconds across, but this will be offset by
the fact that Mars will be about 15° lower in the
sky with a maximum altitude of only 33°. Despite
this, on nights of steady seeing there should
still be plenty of details to see on the surface
with your telescope.
Scope size mattersThrough a telescope with a 4-inch or smaller
aperture and with high magnifcation, you should
see the reddish disc and the small brilliantly white
Þ Mars’s striking albedo features are easily seen, especially through a large telescope
Mare Cimmerium
Mare Tyrrhenum
Mare Hadriacum
ArabiaEden
Mare Serpentis
Syrtis Major
Syrtis Minor
Sinus Meridiani
Sinus Sabaeus
Aurorae Sinus
Elysium
Utopia
Baltia
Amazonis
Mare Erythraeum
Arcadia
Tharsis
Niliacus Lacus
Solis Lacus
ArgyreEridania
Ausonia
Mare Acidalium
da
mia
n p
ea
ch
, m
arti
n l
ew
is, c
ha
rt
by p
ete
la
wren
ce,
ste
ve m
arsh
N
E
42
skyatnightmagazine.com 2014
Mars, that most captivating of planets,
visits our evening sky this spring,
reaching opposition in the constellation
of Virgo on 8 April. The Red Planet is
the only world in the Solar System that readily
reveals details of its rocky surface when viewed
from Earth and this, together with a multitude of
seasonal changes, makes it a fascinating planet to
observe. At opposition, when Mars is at its nearest,
it will shine as a ruddy beacon beckoning you to
view, but be warned, the Mars observing season is
relatively short. Once April is over, the planet appears
to shrink noticeably from week to week and by mid-
August it is all but lost, low in the evening twilight.
Around opposition, Mars will shine at mag.
–1.5, making it just as brilliant as the brightest
star in the night sky. The planet’s reddish colour
will be immediately apparent to the naked eye
and even more obvious in binoculars. Even at
opposition, however, it is unlikely you will see
any surface features in binoculars: for that you
will need a telescope.
When you look through the eyepiece of your
telescope what details on Mars might you be able to
see? The answer to this depends on the size of your
telescope and how steady your skies are, but also
on the planet’s apparent size and its height above
your horizon. Due to Mars’s noticeably elliptical
orbit, its size at opposition can vary by nearly a
factor of two. At its closest, Mars can be as large
as 25 arcseconds across, over half the apparent
diameter of the gas giant Jupiter. Unfortunately for
northern hemisphere observers, these very close
Mars oppositions always occur when the planet is
far south in the sky. Frustratingly for us in the
UK, this means that it then never gets particularly
high in our skies. A low altitude means the view
is much more affected by atmospheric turbulence
and this softens the view, blurring fne surface
detail, and stopping us making the most of
these close approaches.
The previous opposition in 2012 was certainly
not a close one. Mars was nearly at aphelion, its
farthest point from the Sun; at best the planet was
only 14 arcseconds across. However, to make up
for its small size, the planet was well north of the
celestial equator. This meant it was quite high in
our skies, helping us to see good surface details.
During this year’s opposition it will be larger, at
15.1 arcseconds across, but this will be offset by
the fact that Mars will be about 15° lower in the
sky with a maximum altitude of only 33°. Despite
this, on nights of steady seeing there should
still be plenty of details to see on the surface
with your telescope.
Scope size mattersThrough a telescope with a 4-inch or smaller
aperture and with high magnifcation, you should
see the reddish disc and the small brilliantly white
Þ Mars’s striking albedo features are easily seen, especially through a large telescope
Mare Cimmerium
Mare Tyrrhenum
Mare Hadriacum
ArabiaEden
Mare Serpentis
Syrtis Major
Syrtis Minor
Sinus Meridiani
Sinus Sabaeus
Aurorae Sinus
Elysium
Utopia
Baltia
Amazonis
Mare Erythraeum
Arcadia
Tharsis
Niliacus Lacus
Solis Lacus
ArgyreEridania
Ausonia
Mare Acidalium
da
mia
n p
ea
ch
, m
arti
n l
ew
is,
ch
art
by p
ete
la
wren
ce,
ste
ve m
arsh
N
E
VIRGO
Spica
ArcturusBOÖTES
SERPENSCAPUT
LIBRA
CORVUS
CRATER
OPHIUCHUS
HYDRA
Porrima
1 AprMars
30 Apr
Saturn
SE S
mars at opposition april 43
skyatnightmagazine.com 2014
north polar ice cap, which is tilted towards us at
the moment. You should also see one or two of the
more prominent darker features on the surface such
as the wedge-shaped region known as the Syrtis
Major, or the Mare Acidalium, a large shield-shaped
darker region in the northern hemisphere. These
dark albedo features are generally areas where the
Martian wind has swept away most of the lighter,
reddish, desert dust, revealing the darker rocky
surface underneath. Such features change subtly
from season to season as the dust is moved around
but it is unlikely you will see much sign of these
variations in a small telescope.
Telescopes with 6-inch or larger apertures
can reveal much more detail on the planet,
particularly on nights of very good seeing. This
includes the obvious seasonal effects that stem
from the fact that Mars’s axis is tilted to a similar
degree to Earth’s. Martian seasons are always one
ahead of those on Earth, meaning Mars’s northern
hemisphere is now moving towards mid-summer.
This means that the north polar cap, which is tilted
towards the Sun and Earth, is shrinking. Through
your telescope you may be able to see the shape as
well as the size of the polar cap and possibly detect
a darker band where the snows have retreated
around the pole.
The dark albedo surface features are also better
seen in larger telescopes. Depending on which side
is facing Earth, exotic sounding features like the
Sinus Sebaeus, Utopia and Aurorae Sinus may be
visible. You may also see several other distinctive
areas identifed on the accompanying albedo map,
shown left. A red flter (Wratten number #25),
screwed into the eyepiece or held between your
eye and the eyepiece, may help you pick out the
more diffcult of these albedo features. The flter
will increase the contrast by darkening the features
relative to the redder background. If the seeing
is good don’t be afraid to increase the eyepiece
magnifcation to pull out more detail. The best
thing is to experiment – you’ll know that you’ve
gone too far when the detail starts to blur out
rather than improve.
þ Just like the Moon, Mars is covered in recognisable named surface features
Þ Attaching a Wratten #25 red flter to your eyepiece can help to reveal less-obvious dark albedo features
Pavonis Lacus
Olympus Mons
Scandia
Amazonis
Mare Sirenum
>
Þ Approximate sky orientation for 1, 15 and 30 April at 01:00 BST, 00:00 BST and 23:00 BST respectively
VIRGO
Spica
ArcturusBOÖTES
SERPENSCAPUT
LIBRA
CORVUS
CRATER
OPHIUCHUS
HYDRA
Porrima
1 AprMars
30 Apr
Saturn
SE S
mars at opposition april 43
skyatnightmagazine.com 2014
north polar ice cap, which is tilted towards us at
the moment. You should also see one or two of the
more prominent darker features on the surface such
as the wedge-shaped region known as the Syrtis
Major, or the Mare Acidalium, a large shield-shaped
darker region in the northern hemisphere. These
dark albedo features are generally areas where the
Martian wind has swept away most of the lighter,
reddish, desert dust, revealing the darker rocky
surface underneath. Such features change subtly
from season to season as the dust is moved around
but it is unlikely you will see much sign of these
variations in a small telescope.
Telescopes with 6-inch or larger apertures
can reveal much more detail on the planet,
particularly on nights of very good seeing. This
includes the obvious seasonal effects that stem
from the fact that Mars’s axis is tilted to a similar
degree to Earth’s. Martian seasons are always one
ahead of those on Earth, meaning Mars’s northern
hemisphere is now moving towards mid-summer.
This means that the north polar cap, which is tilted
towards the Sun and Earth, is shrinking. Through
your telescope you may be able to see the shape as
well as the size of the polar cap and possibly detect
a darker band where the snows have retreated
around the pole.
The dark albedo surface features are also better
seen in larger telescopes. Depending on which side
is facing Earth, exotic sounding features like the
Sinus Sebaeus, Utopia and Aurorae Sinus may be
visible. You may also see several other distinctive
areas identifed on the accompanying albedo map,
shown left. A red flter (Wratten number #25),
screwed into the eyepiece or held between your
eye and the eyepiece, may help you pick out the
more diffcult of these albedo features. The flter
will increase the contrast by darkening the features
relative to the redder background. If the seeing
is good don’t be afraid to increase the eyepiece
magnifcation to pull out more detail. The best
thing is to experiment – you’ll know that you’ve
gone too far when the detail starts to blur out
rather than improve.
þ Just like the Moon, Mars is covered in recognisable named surface features
Þ Attaching a Wratten #25 red flter to your eyepiece can help to reveal less-obvious dark albedo features
Pavonis Lacus
Olympus Mons
Scandia
Amazonis
Mare Sirenum
>
Þ Approximate sky orientation for 1, 15 and 30 April at 01:00 BST, 00:00 BST and 23:00 BST respectively
44
skyatnightmagazine.com 2014
da
mia
n p
ea
ch
x 3
, m
arti
n l
ew
is x
4, d
av
e h
olt
, ste
ve m
arsh
x 3
Local dust storms are
another Martian feature to
look out for in large scopes.
Strong winds whip up the
surface dust and push it into
Mars’s atmosphere. These
dust storm areas appear
through the telescope as
signifcantly brighter orange-
yellow areas, which change
between one day and the next.
The dust may mask the normal albedo
features in an area and these storms can
sometimes even go global, turning the planet into
an almost featureless orange ball. One or two local
dust events may be seen during this opposition,
but the bigger global dust storms are not likely;
they only really occur in August and September,
when the planet is closer to the Sun and it receives
the extra heat necessary to power these events.
Chasing cloudsMany people are surprised that ice clouds or haze
can sometimes be seen on Mars – you can read more
about the Red Planet’s atmosphere on page 34.
These features are seasonally related and again
flters help improve their contrast. A blue flter
(Wratten number #80A or #38A) is best to use here
as it darkens the red areas compared to the more
bluish clouds. Hazy cloud tends to appear in the
early morning and evening, and so will be seen at
the western or eastern edges of the planet. Blue
hazy clouds also occur around the polar regions, so
examine the entire edge of the planet with and
without the blue flter to see if you can see signs
of these changing atmospheric features.
During the 2012 opposition, an extensive area
of whitish morning cloud was evident in the
low-lying Tharsis region of Mars. This region is
home to several huge volcanoes, and these have
been seen
to poke holes
through the cloud
layer. Imaging with a
high frame rate camera
may be needed to make such
features visible, as they will be small
and this type of imaging allows you to see more on
the planet than you can through visual observing
(see ‘Imaging Mars’, right).
A different type of cloud to the morning and
evening hazes are the so-called orographic clouds,
which form over high regions and are sometimes
seen centred on some of the larger Martian
volcanoes. During the 2005 opposition Olympus
Mons, the highest volcano in the Solar System at
27km, had a persistent orographic cloud around
it that was easily seen as a small white patch.
TOP: In 2005 large orographic white clouds were visible above prominent features on Mars. Here we see Olympus Mons as a clear white dot in the upper right quadrant with the clouds hovering over it. MIDDLE: The 2007 apparition of Mars began with the planet shrouded in a huge dust storm. This meant surface features were diffcult to resolve. The dust storm cleared as the planet reached opposition. BOTTOM: Beautiful wispy white clouds were on show during the 2012 opposition period, particularly over Olympus Mons and the Tharsis volcano region, which are visible across the centre of the planet.
>
44
skyatnightmagazine.com 2014
da
mia
n p
ea
ch
x 3
, m
arti
n l
ew
is x
4,
da
ve h
olt
, ste
ve m
arsh
x 3
Local dust storms are
another Martian feature to
look out for in large scopes.
Strong winds whip up the
surface dust and push it into
Mars’s atmosphere. These
dust storm areas appear
through the telescope as
signifcantly brighter orange-
yellow areas, which change
between one day and the next.
The dust may mask the normal albedo
features in an area and these storms can
sometimes even go global, turning the planet into
an almost featureless orange ball. One or two local
dust events may be seen during this opposition,
but the bigger global dust storms are not likely;
they only really occur in August and September,
when the planet is closer to the Sun and it receives
the extra heat necessary to power these events.
Chasing cloudsMany people are surprised that ice clouds or haze
can sometimes be seen on Mars – you can read more
about the Red Planet’s atmosphere on page 34.
These features are seasonally related and again
flters help improve their contrast. A blue flter
(Wratten number #80A or #38A) is best to use here
as it darkens the red areas compared to the more
bluish clouds. Hazy cloud tends to appear in the
early morning and evening, and so will be seen at
the western or eastern edges of the planet. Blue
hazy clouds also occur around the polar regions, so
examine the entire edge of the planet with and
without the blue flter to see if you can see signs
of these changing atmospheric features.
During the 2012 opposition, an extensive area
of whitish morning cloud was evident in the
low-lying Tharsis region of Mars. This region is
home to several huge volcanoes, and these have
been seen
to poke holes
through the cloud
layer. Imaging with a
high frame rate camera
may be needed to make such
features visible, as they will be small
and this type of imaging allows you to see more on
the planet than you can through visual observing
(see ‘Imaging Mars’, right).
A different type of cloud to the morning and
evening hazes are the so-called orographic clouds,
which form over high regions and are sometimes
seen centred on some of the larger Martian
volcanoes. During the 2005 opposition Olympus
Mons, the highest volcano in the Solar System at
27km, had a persistent orographic cloud around
it that was easily seen as a small white patch.
TOP: In 2005 large orographic white clouds were visible above prominent features on Mars. Here we see Olympus Mons as a clear white dot in the upper right quadrant with the clouds hovering over it. MIDDLE: The 2007 apparition of Mars began with the planet shrouded in a huge dust storm. This meant surface features were diffcult to resolve. The dust storm cleared as the planet reached opposition. BOTTOM: Beautiful wispy white clouds were on show during the 2012 opposition period, particularly over Olympus Mons and the Tharsis volcano region, which are visible across the centre of the planet.
>
mars at opposition april 45
skyatnightmagazine.com 2014
tHE four faCEs OF MARSthrough a telescope, look for mars’s prominent features to work out which region you are looking at. these images are from the 2012 apparition with the north pole at the bottom
iMAging mars
The best way to image planets is to record a video through your telescope using a high frame rate planetary camera and a Barlow lens, then processing the resulting movie to create a high-resolution still image. The fnal image uses only the best moments of seeing and disregards the poor ones, and reveals much more surface detail than you could hope to see through the eyepiece of the same scope. For the best images you can even try using an atmospheric dispersion corrector, which reduces the prismatic effect of our atmosphere; an important consideration given Mars’s lower altitude this apparition.
Colour cameras give slightly less detail than their mono counterparts, but they do dramatically speed up and simplify both the imaging process and the follow-up processing needed. Mars is a relatively easy planet to capture; as long as the atmosphere is steady you should be able to get
interesting images through any driven telescope, although larger instruments will be able to show more detail.
Mars’s high surface brightness allows you to increase the image scale. For cameras with the popular pixel size of 5.6μm, try a Barlow lens that gives effective focal ratios of f/25 to f/35, or even up to f/50 on exceptionally steady nights. For cameras with smaller pixel sizes, drop these focal ratio values in proportion to the pixel size. The Red Planet completes one rotation in 24 hours and 37 minutes; so long as you complete your imaging within fve minutes, you will avoid motion blur.
To fnd out how to image Mars with a mono CCD camera, turn to page 64.
If you see signifcant detail on the planet, have a
go at making a sketch of what you see at the eyepiece.
First spend some time looking without committing
anything to paper. This will let you to tune into the
scene allowing details to slowly reveal themselves.
It’s a good idea to prepare some blanks in advance,
so draw 50mm circles on good-quality cartridge
paper before you observe. It’s also worth using good
quality HB, B and perhaps 2B pencils. You could
even use coloured pencils to depict some of the
different hues present if you’re feeling ambitious.
Mars takes 24 hours and 37 minutes to complete
a rotation, so you can take your time sketching
before the face on show changes noticeably. The
1 Syrtis Major (Central longitude: 320º)
This is the classic view of Mars, showing the prominent dark wedge shape of the Syrtis Major with the pipe-like Sinus Sabaeus off to the right.
2 Mare Cimmerium (Central longitude: 198°)
After 11 days, the Mare Cimmerium is on view at the top. On the left, cloud over Olympus Mons shows up as a white patch. The Amazonis desert flls the centre.
3 Eye of Mars (Central longitude: 82°)
Ten days later, Solis Lacus, known as the ‘Eye of Mars’, is seen at the top left and the dark fngers of Aurorae Sinus are seen upper left. The Mare Acidalium is lower left.
4 Mare Acidalium (Central longitude: 23°)
Another seven days on and the large shield-shaped Mare Acidalium sits above the north polar cap, while the Sinus Sabaeus reappears on the left-hand side.
Þ Stacking single frames from a video (left) creates a high-resolution image (right)
Þ With so much observing potential, sketching the Red Planet is a uniquely rewarding challenge
>
Þ A 3x Barlow attached to a high frame
rate planetary imaging camera
mars at opposition april 45
skyatnightmagazine.com 2014
tHE four faCEs OF MARSthrough a telescope, look for mars’s prominent features to work out which region you are looking at. these images are from the 2012 apparition with the north pole at the bottom
iMAging mars
The best way to image planets is to record a video through your telescope using a high frame rate planetary camera and a Barlow lens, then processing the resulting movie to create a high-resolution still image. The fnal image uses only the best moments of seeing and disregards the poor ones, and reveals much more surface detail than you could hope to see through the eyepiece of the same scope. For the best images you can even try using an atmospheric dispersion corrector, which reduces the prismatic effect of our atmosphere; an important consideration given Mars’s lower altitude this apparition.
Colour cameras give slightly less detail than their mono counterparts, but they do dramatically speed up and simplify both the imaging process and the follow-up processing needed. Mars is a relatively easy planet to capture; as long as the atmosphere is steady you should be able to get
interesting images through any driven telescope, although larger instruments will be able to show more detail.
Mars’s high surface brightness allows you to increase the image scale. For cameras with the popular pixel size of 5.6μm, try a Barlow lens that gives effective focal ratios of f/25 to f/35, or even up to f/50 on exceptionally steady nights. For cameras with smaller pixel sizes, drop these focal ratio values in proportion to the pixel size. The Red Planet completes one rotation in 24 hours and 37 minutes; so long as you complete your imaging within fve minutes, you will avoid motion blur.
To fnd out how to image Mars with a mono CCD camera, turn to page 64.
If you see signifcant detail on the planet, have a
go at making a sketch of what you see at the eyepiece.
First spend some time looking without committing
anything to paper. This will let you to tune into the
scene allowing details to slowly reveal themselves.
It’s a good idea to prepare some blanks in advance,
so draw 50mm circles on good-quality cartridge
paper before you observe. It’s also worth using good
quality HB, B and perhaps 2B pencils. You could
even use coloured pencils to depict some of the
different hues present if you’re feeling ambitious.
Mars takes 24 hours and 37 minutes to complete
a rotation, so you can take your time sketching
before the face on show changes noticeably. The
1 Syrtis Major (Central longitude: 320º)
This is the classic view of Mars, showing the prominent dark wedge shape of the Syrtis Major with the pipe-like Sinus Sabaeus off to the right.
2 Mare Cimmerium (Central longitude: 198°)
After 11 days, the Mare Cimmerium is on view at the top. On the left, cloud over Olympus Mons shows up as a white patch. The Amazonis desert flls the centre.
3 Eye of Mars (Central longitude: 82°)
Ten days later, Solis Lacus, known as the ‘Eye of Mars’, is seen at the top left and the dark fngers of Aurorae Sinus are seen upper left. The Mare Acidalium is lower left.
4 Mare Acidalium (Central longitude: 23°)
Another seven days on and the large shield-shaped Mare Acidalium sits above the north polar cap, while the Sinus Sabaeus reappears on the left-hand side.
Þ Stacking single frames from a video (left) creates a high-resolution image (right)
Þ With so much observing potential, sketching the Red Planet is a uniquely rewarding challenge
>
Þ A 3x Barlow attached to a high frame
rate planetary imaging camera
46 mars at opposition april
skyatnightmagazine.com 2014
traCking bAckwARdS
ABOUT THE WRITER
martin lewis is a keen astronomer. as a frequent reviewer for our First Light section, he has an in-depth knowledge of observing the planets with all sorts of equipment.
fact that the Martian day is about 40 minutes longer
than ours on Earth means that the planet appears to
rotate slowly backwards as the days pass. This
difference between a Martian day and an Earth day
also means that you need to wait about fve weeks for
the same face to come into view again if you observe
Mars at its highest each evening. A bit of planning is
needed, therefore, if you want to see the whole of
the Martian globe this spring.
Brief opportunityMars will be more than 15 arcseconds across from
5-23 April and in the middle of this period it will
be highest in the sky half an hour after midnight.
By the end of May, however, it will have shrunk to
less than 12 arcseconds across and will be an hour
past its highest position when it gets dark at 10pm.
Mars is a fascinating planet with its albedo features
and multitude of seasonal changes, so make the most
of April and May to see what you can make out on
the surface of this kindred world. If you are able to,
make some record of the planet’s details this time
around. You can then see what changes occur between
now and May 2016, the next time it’ll be at its closest.
AppARent diamEtErAlthough Mars oppositions occur at regular 26-month intervals, the apparent size of the planet at this time can vary widely, from just over 25 arcseconds to
a little less than 14 arcseconds. This is due to Mars’s elliptical orbit, which causes the Mars-to-Earth distance to be as little as 0.37 AU or as much as 0.67 AU.
The planets orbiting the Sun farther than Earth generally track slowly eastwards through the constellations as the months pass. For several weeks either side of opposition, however, they appear to change direction and move westward, before later resuming their eastward track. The period where they seem to move in reverse is called retrograde motion. It occurs because the faster-moving Earth overtakes a more distant planet, making it appear to move
backwards against the stars. You might see a similar effect on the motorway when overtaking a slower moving car – it appears to move backwards against the more distant scenery. During this apparition, Mars moves in a retrograde direction from 27 February to 18 May, from six weeks before opposition to six weeks after opposition, before recommencing its eastwards track towards Libra.
East
WestEast
Mars
Earth
Sun
Þ As Earth overtakes Mars, the Red Planet appears to move backwards against the stars
S
>
VIRGO
Spica
Porrima
1 Jan
1 Feb
1 Mar
1 Apr
1 May 1 Jun
1 Jul
8 Apr(Opposition)
Mars
α
γ
ζ
η
τ
θ
ch
art
by
pete
la
wre
nc
e, il
lust
ra
tio
ns
by s
tev
e m
ars
h
13 Oct 2020 22.4 arcseconds
27 Jul 2018 24.2 arcseconds
22 May 2016 18.4 arcseconds
8 Apr 2014 15.1 arcseconds
3 Mar 2012 13.9 arcseconds
19 Feb 2027 13.8 arcseconds
16 Jan 2025 14.5 arcseconds
8 Dec 2022 17.0 arcseconds
M
ars
Eart
h
Ven
us
Mer
cury
Mars’s path from the beginning of year through to July 2014
46 mars at opposition april
skyatnightmagazine.com 2014
traCking bAckwARdS
ABOUT THE WRITER
martin lewis is a keen astronomer. as a frequent reviewer for our First Light section, he has an in-depth knowledge of observing the planets with all sorts of equipment.
fact that the Martian day is about 40 minutes longer
than ours on Earth means that the planet appears to
rotate slowly backwards as the days pass. This
difference between a Martian day and an Earth day
also means that you need to wait about fve weeks for
the same face to come into view again if you observe
Mars at its highest each evening. A bit of planning is
needed, therefore, if you want to see the whole of
the Martian globe this spring.
Brief opportunityMars will be more than 15 arcseconds across from
5-23 April and in the middle of this period it will
be highest in the sky half an hour after midnight.
By the end of May, however, it will have shrunk to
less than 12 arcseconds across and will be an hour
past its highest position when it gets dark at 10pm.
Mars is a fascinating planet with its albedo features
and multitude of seasonal changes, so make the most
of April and May to see what you can make out on
the surface of this kindred world. If you are able to,
make some record of the planet’s details this time
around. You can then see what changes occur between
now and May 2016, the next time it’ll be at its closest.
AppARent diamEtErAlthough Mars oppositions occur at regular 26-month intervals, the apparent size of the planet at this time can vary widely, from just over 25 arcseconds to
a little less than 14 arcseconds. This is due to Mars’s elliptical orbit, which causes the Mars-to-Earth distance to be as little as 0.37 AU or as much as 0.67 AU.
The planets orbiting the Sun farther than Earth generally track slowly eastwards through the constellations as the months pass. For several weeks either side of opposition, however, they appear to change direction and move westward, before later resuming their eastward track. The period where they seem to move in reverse is called retrograde motion. It occurs because the faster-moving Earth overtakes a more distant planet, making it appear to move
backwards against the stars. You might see a similar effect on the motorway when overtaking a slower moving car – it appears to move backwards against the more distant scenery. During this apparition, Mars moves in a retrograde direction from 27 February to 18 May, from six weeks before opposition to six weeks after opposition, before recommencing its eastwards track towards Libra.
East
WestEast
Mars
Earth
Sun
Þ As Earth overtakes Mars, the Red Planet appears to move backwards against the stars
S
>
VIRGO
Spica
Porrima
1 Jan
1 Feb
1 Mar
1 Apr
1 May 1 Jun
1 Jul
8 Apr(Opposition)
Mars
α
γ
ζ
η
τ
θ
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by
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by s
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ars
h
13 Oct 2020 22.4 arcseconds
27 Jul 2018 24.2 arcseconds
22 May 2016 18.4 arcseconds
8 Apr 2014 15.1 arcseconds
3 Mar 2012 13.9 arcseconds
19 Feb 2027 13.8 arcseconds
16 Jan 2025 14.5 arcseconds
8 Dec 2022 17.0 arcseconds
M
ars
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Ven
us
Mer
cury
Mars’s path from the beginning of year through to July 2014
www.MORRISPHOTO.co.ukTel: 08454 30 20 30 Helpline: 01608 649224 Unit 9, Worcester Road Ind Est, CHIPPING NORTON. Oxon. OX7 5XW.
Fax: 01608 644555 Email: sales@morrisphoto.co.ukVisit our website, but if you prefer to call in person our showroom is open Mon-Sat 9am-5pm (Tue 9.30-5pm).
Seen a better price - ask us to match or better All prices valid whilst stocks last and include VAT @ current rate. E&OE.
Dedicated Astronomy section now live on www.morrisphoto.co.uk Magnifications (with optics supplied): x36,
x72, x90, x180. Diameter Primary Mirror: 130mm. Telescope Focal Length: 900mm (f/6.92).Telescope Focal Length: 900mm (f/6.92).
EQ2 Equatorial Mount. R.A. Motor Drive (D.C.) with Multi-Speed Handset. Uses T mount to attach your digital or film SLR.Skywatcher Explorer130M
Newtonian Reflector Telescope £see webMORE SKYWATCHER PRODUCTS
Skyhawk 1145P Sync Scan AZ Go-To Computerised Telescope SAVE £15 £254.99Heritage 76 Mini DobsonianTelescope SAVE £36 £43.10Heritage 130P Mini DobsonianTelescope SAVE £31 £128.90Heritage 114P Virtuoso Auto TrackingTelescope SAVE £20 £179.95
17AH Rechargeable Power Tank SAVE £10 £109.95
7AH Rechargeable Power Tank SAVE £3 £56.95
1.25” Deluxe Barlow Lens X2 (Double Lens) SAVE £7 £28.991.25” Economy Barlow Lens X2 (Single Lens) SAVE £3 £14.991.25” Lunar/Planetary Filter Set SAVE £3 £26.991.25” Tele Extender SAVE £5 £35.00Light Pollution Filters 1.25/2” SAVE £2 £17.99Moon Filter 1.25” SAVE £1.50 £8.50Electronic Shutter Release Cable To Fit Most Camera Models £6.99Prime Focus Camera Adapter SAVE £7 £24.99
SKYWATCHER EXPLORER 130M
Please note we are just outside the town centre on Worcester Road. FREE PARKING is available outside our premises.
MORE SKYWATCHER PRODUCTSUniversal Camera Adapter £29.957.5, 10, 11.5, 17, 20mm ‘SR Series’ Super Plossi Eyepieces (Each) SAVE £3 £21.9932, 40mm ‘SR Series’ Super Plossi Eyepieces (Each) SAVE £3 £31.99Red Dot Finder SAVE £1 £23.99
Optical design: reflector. Aperture: 130 mm. Focal length: 650 mm. Focal ratio: 5.Eyepiece 1:20mm. Magnification 1:32.5 x.
Eyepiece 2: 10mm. Magnification 2: 65 xMount: CG-3 Equatorial. Motor drive: Included. Optical coatings: multi coated.
Weight: 10.89 kg.Astromaster 130EQ MD Telescope SAVE £87 £142.90
MORE CELESTRON PRODUCTSAstromaster 130EQ Telescope SAVE £65 £135.00LCM114 Computerised Telescope SAVE £71 £279.00LCM80 Computerised Telescope SAVE £128 £229.00
Firstscope 76 SAVE £50 £39.95
Firstscope Accessory Kit SAVE £5 £16.97
Astromaster Accessory Kit SAVE £33 £47.00Astromaster Motor Drive £49.99Omni 2x Barlow Lens SAVE £10 £41.99Moon Filter £8.55Universal T Adapter £20.95T Camera Ring (Major Brands) Each £12.99
CELESTRON ASTROMASTER 130EQ MD
FREE UK Mainland P&P orders over £49
1400mm compact tube. 150mm (6”) mirror. Basic 6mm eyepiece (233x magnification). Tripod and equatorial mount- Finderscope. Basic 25mm
eyepiece (56x magnification) with built in erecting lens. Includes the M-2 Visionary
Motor Unit for EQ2 with a hand controller.Mira Ceti 6” 1400mm/150mm
Telescope With M2 Motor Unit £274.95MORE VISIONARY PRODUCTS
Mira Ceti 6” 1400mm/150mmTelescope £224.95
Telesto Full Size Telescope With M1 Motor £154.99
Telesto Full Size Telescope £124.99
Firstview 76mm Telescope £34.99M2 Motor Unit For EQ2 Mount £57.99 M1 Motor Unit For EQ1 Mount £28.99
VISIONARY MIRA CETI 150 M2 MOTOROptical system Reflector. Mirror diameter
130mm. Focal length 650mm. Mount equatorial. Magnification 26x-195x.
Eyepieces K-10/K-25MM. Viewfinder LED.Barlow lens 3x. Moon filter. Star map. Tripod. Astronomy software.Newton 130/650 Telescope With Accessories £179.00
MORE NG PRODUCTS76/350 Compact Telescope SAVE £20 £39.95
NATIONAL GEOGRAPHIC NEWTON 130/650
The NG Astro Planetarium allows you to view the nightsky in your own room! It will project the nightsky onto your ceiling, actually
true to time and day. There are two different star slide discs for variety,
and the two integrated motors keep the projected image in motion. There is also a 2.0 speaker system to connect a digital music player.Planetarium SAVE £19 £69.00
NATIONAL GEOGRAPHIC PLANETARIUM
£5In-Store Voucher When You Spend
Over £49
Why not visit - we are in a beautiful part of the world! Use this voucher to save £5 when you spend over £49 in store. Only one voucher per customer, not available for mail order. Voucher has no monetary
value - not redeemable for cash. Valid till 31st March 2014.
Astronomy Now March 2014
The 15x magnification is ideal as a long range observation or security
binocular. This model is designed to give high clarity, very high power
and a natural, true to life colour due to multi coated lenses. High Resolution BAK4 prisms ensure a brighter image throughout the range of magnifications by maximising light transmission. Efficient use of the light gathered is particularly important at high magnifications where images appear darker.10 x 50 HD Binoculars £59.9715 x 70 HD Binoculars £84.9720 x 80 HD Binoculars £149.97
VISIONARY 15x70 HD BINOCULARS
The UK’s Telescope & Equipment Specialists
Call 01223 911150 (local rate) for friendly
advice and phone order
Great Service and Best PricesWe ofer a wide range of telescopes and accessories for all your star-gazing needs,
beginners and experts alike, at our best prices – with free shipping (orders over £50 in UK mainland)
Get expert, friendly advice to select the right equipment for your requirements.
01223 911150 | www.astronomycentre.co.uk | enquiries@astronomycentre.co.uk
We are ofcial dealers for
www.MORRISPHOTO.co.ukTel: 08454 30 20 30 Helpline: 01608 649224 Unit 9, Worcester Road Ind Est, CHIPPING NORTON. Oxon. OX7 5XW.
Fax: 01608 644555 Email: sales@morrisphoto.co.ukVisit our website, but if you prefer to call in person our showroom is open Mon-Sat 9am-5pm (Tue 9.30-5pm).
Seen a better price - ask us to match or better All prices valid whilst stocks last and include VAT @ current rate. E&OE.
Dedicated Astronomy section now live on www.morrisphoto.co.uk Magnifications (with optics supplied): x36,
x72, x90, x180. Diameter Primary Mirror: 130mm. Telescope Focal Length: 900mm (f/6.92).Telescope Focal Length: 900mm (f/6.92).
EQ2 Equatorial Mount. R.A. Motor Drive (D.C.) with Multi-Speed Handset. Uses T mount to attach your digital or film SLR.Skywatcher Explorer130M
Newtonian Reflector Telescope £see webMORE SKYWATCHER PRODUCTS
Skyhawk 1145P Sync Scan AZ Go-To Computerised Telescope SAVE £15 £254.99Heritage 76 Mini DobsonianTelescope SAVE £36 £43.10Heritage 130P Mini DobsonianTelescope SAVE £31 £128.90Heritage 114P Virtuoso Auto TrackingTelescope SAVE £20 £179.95
17AH Rechargeable Power Tank SAVE £10 £109.95
7AH Rechargeable Power Tank SAVE £3 £56.95
1.25” Deluxe Barlow Lens X2 (Double Lens) SAVE £7 £28.991.25” Economy Barlow Lens X2 (Single Lens) SAVE £3 £14.991.25” Lunar/Planetary Filter Set SAVE £3 £26.991.25” Tele Extender SAVE £5 £35.00Light Pollution Filters 1.25/2” SAVE £2 £17.99Moon Filter 1.25” SAVE £1.50 £8.50Electronic Shutter Release Cable To Fit Most Camera Models £6.99Prime Focus Camera Adapter SAVE £7 £24.99
SKYWATCHER EXPLORER 130M
Please note we are just outside the town centre on Worcester Road. FREE PARKING is available outside our premises.
MORE SKYWATCHER PRODUCTSUniversal Camera Adapter £29.957.5, 10, 11.5, 17, 20mm ‘SR Series’ Super Plossi Eyepieces (Each) SAVE £3 £21.9932, 40mm ‘SR Series’ Super Plossi Eyepieces (Each) SAVE £3 £31.99Red Dot Finder SAVE £1 £23.99
Optical design: reflector. Aperture: 130 mm. Focal length: 650 mm. Focal ratio: 5.Eyepiece 1:20mm. Magnification 1:32.5 x.
Eyepiece 2: 10mm. Magnification 2: 65 xMount: CG-3 Equatorial. Motor drive: Included. Optical coatings: multi coated.
Weight: 10.89 kg.Astromaster 130EQ MD Telescope SAVE £87 £142.90
MORE CELESTRON PRODUCTSAstromaster 130EQ Telescope SAVE £65 £135.00LCM114 Computerised Telescope SAVE £71 £279.00LCM80 Computerised Telescope SAVE £128 £229.00
Firstscope 76 SAVE £50 £39.95
Firstscope Accessory Kit SAVE £5 £16.97
Astromaster Accessory Kit SAVE £33 £47.00Astromaster Motor Drive £49.99Omni 2x Barlow Lens SAVE £10 £41.99Moon Filter £8.55Universal T Adapter £20.95T Camera Ring (Major Brands) Each £12.99
CELESTRON ASTROMASTER 130EQ MD
FREE UK Mainland P&P orders over £49
1400mm compact tube. 150mm (6”) mirror. Basic 6mm eyepiece (233x magnification). Tripod and equatorial mount- Finderscope. Basic 25mm
eyepiece (56x magnification) with built in erecting lens. Includes the M-2 Visionary
Motor Unit for EQ2 with a hand controller.Mira Ceti 6” 1400mm/150mm
Telescope With M2 Motor Unit £274.95MORE VISIONARY PRODUCTS
Mira Ceti 6” 1400mm/150mmTelescope £224.95
Telesto Full Size Telescope With M1 Motor £154.99
Telesto Full Size Telescope £124.99
Firstview 76mm Telescope £34.99M2 Motor Unit For EQ2 Mount £57.99 M1 Motor Unit For EQ1 Mount £28.99
VISIONARY MIRA CETI 150 M2 MOTOROptical system Reflector. Mirror diameter
130mm. Focal length 650mm. Mount equatorial. Magnification 26x-195x.
Eyepieces K-10/K-25MM. Viewfinder LED.Barlow lens 3x. Moon filter. Star map. Tripod. Astronomy software.Newton 130/650 Telescope With Accessories £179.00
MORE NG PRODUCTS76/350 Compact Telescope SAVE £20 £39.95
NATIONAL GEOGRAPHIC NEWTON 130/650
The NG Astro Planetarium allows you to view the nightsky in your own room! It will project the nightsky onto your ceiling, actually
true to time and day. There are two different star slide discs for variety,
and the two integrated motors keep the projected image in motion. There is also a 2.0 speaker system to connect a digital music player.Planetarium SAVE £19 £69.00
NATIONAL GEOGRAPHIC PLANETARIUM
£5In-Store Voucher When You Spend
Over £49
Why not visit - we are in a beautiful part of the world! Use this voucher to save £5 when you spend over £49 in store. Only one voucher per customer, not available for mail order. Voucher has no monetary
value - not redeemable for cash. Valid till 31st March 2014.
Astronomy Now March 2014
The 15x magnification is ideal as a long range observation or security
binocular. This model is designed to give high clarity, very high power
and a natural, true to life colour due to multi coated lenses. High Resolution BAK4 prisms ensure a brighter image throughout the range of magnifications by maximising light transmission. Efficient use of the light gathered is particularly important at high magnifications where images appear darker.10 x 50 HD Binoculars £59.9715 x 70 HD Binoculars £84.9720 x 80 HD Binoculars £149.97
VISIONARY 15x70 HD BINOCULARS
The UK’s Telescope & Equipment Specialists
Call 01223 911150 (local rate) for friendly
advice and phone order
Great Service and Best PricesWe ofer a wide range of telescopes and accessories for all your star-gazing needs,
beginners and experts alike, at our best prices – with free shipping (orders over £50 in UK mainland)
Get expert, friendly advice to select the right equipment for your requirements.
01223 911150 | www.astronomycentre.co.uk | enquiries@astronomycentre.co.uk
We are ofcial dealers for
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WHERE TO STUDY THE
0161 653 9092 www.planeteartheducation.co.uk
PlanET EaRTH EDUcaTiOn
courses available for enrolment all year round
One of the UK’s most popular and longest standing providers of astronomy distance learning courses. Choose from fve separate astronomy courses, suitable for complete beginner right through to frst-year university standard, including GCSE Astronomy. A certifcate is issued for each completed course. You will fnd a complete syllabus for each of the courses available, along with other details about each course, and the necessary enrolment information on our website. There is a ‘Student Feedback’ link where you can view some of the unsolicited comments we have received from past students. We pride ourselves on being accessible and fexible and offer very attractively priced services, of the highest standards, and we work hard to provide you with what you want. Of paramount importance to us is the one-to-one contact students have with their tutor, who is easily accessible even outside of offce hours.
The UCL Certifcate of Higher Education in Astronomy is taught at the UCL campus in Central London.
The two year course of part-time study requires no subject-related A-level. Study is in UCL’s Physics and Astronomy Department, one evening per week from 6 to 9pm. It has a much greater coverage of astronomy than ordinary evening classes and includes regular practical classes at UCL’s superbly equipped Observatory at Mill Hill.
This course is ideal for keen amateur astronomers, teachers and everyone interested in learning more about astronomy.
The certifcate is endorsed by the Royal Astronomical Society.
Details and application form are linked on the web page below.
020 7679 3943 astrocert@ucl.ac.uk www.ucl.ac.uk/phys/admissions/certifcate
UnivERSiTY cOllEgE lOnDOn
ADVERTISEMENT FEATURE
You can learn more about the Universe by taking an
astronomy course. There’s a wide variety on offer,
covering all age groups and levels of experience,
to help you take your interest further.
WHERE TO STUDY THE
0161 653 9092 www.planeteartheducation.co.uk
PlanET EaRTH EDUcaTiOn
courses available for enrolment all year round
One of the UK’s most popular and longest standing providers of astronomy distance learning courses. Choose from fve separate astronomy courses, suitable for complete beginner right through to frst-year university standard, including GCSE Astronomy. A certifcate is issued for each completed course. You will fnd a complete syllabus for each of the courses available, along with other details about each course, and the necessary enrolment information on our website. There is a ‘Student Feedback’ link where you can view some of the unsolicited comments we have received from past students. We pride ourselves on being accessible and fexible and offer very attractively priced services, of the highest standards, and we work hard to provide you with what you want. Of paramount importance to us is the one-to-one contact students have with their tutor, who is easily accessible even outside of offce hours.
The UCL Certifcate of Higher Education in Astronomy is taught at the UCL campus in Central London.
The two year course of part-time study requires no subject-related A-level. Study is in UCL’s Physics and Astronomy Department, one evening per week from 6 to 9pm. It has a much greater coverage of astronomy than ordinary evening classes and includes regular practical classes at UCL’s superbly equipped Observatory at Mill Hill.
This course is ideal for keen amateur astronomers, teachers and everyone interested in learning more about astronomy.
The certifcate is endorsed by the Royal Astronomical Society.
Details and application form are linked on the web page below.
020 7679 3943 astrocert@ucl.ac.uk www.ucl.ac.uk/phys/admissions/certifcate
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MPhys (4-year) and BSc (3-year) degree programmes including Physics with Astrophysics. The astrophysics options and research project enable you to pursue in-depth knowledge of astrophysics topics. Programmes include hands-on experience using the Department’s suite of optical and radio telescopes. Key teaching and research areas include nuclear astrophysics, fusion and lasers, nanotechnology, computational and theoretical physics.
01904 322241www.york.ac.uk/physics
THE UnivERSiTY Of YORk
Further details are available at:
astro.qmul.ac.uk/teaching/
msc-astrophysics.
Enquiries:
astro-pg@qmul.ac.uk
Tel: 020 7882 6958
As one of the world’s leading providers of distance learning astronomy study, UCLan offers a range of part-time courses starting from University Certifcates up to Honours Degree level. University Certifcates are single-module awards designed for people with no prior knowledge of the subject. They can be used towards more advanced awards leading to our BSc (Hons) Astronomy. Visit www.studyastronomy.com for more information.
UCLan’s BSc (Hons) and MPhys (Hons) Astrophysics, based at our well-appointed and modern campus in Preston, provide essential training in understanding the physical concepts that govern our Universe. Visit www.uclan.ac.uk/courses for more information.
01772 892400 enquiries@uclan.ac.uk www.studyastronomy.com
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MPhys (4-year) and BSc (3-year) degree programmes including Physics with Astrophysics. The astrophysics options and research project enable you to pursue in-depth knowledge of astrophysics topics. Programmes include hands-on experience using the Department’s suite of optical and radio telescopes. Key teaching and research areas include nuclear astrophysics, fusion and lasers, nanotechnology, computational and theoretical physics.
01904 322241www.york.ac.uk/physics
THE UnivERSiTY Of YORk
Further details are available at:
astro.qmul.ac.uk/teaching/
msc-astrophysics.
Enquiries:
astro-pg@qmul.ac.uk
Tel: 020 7882 6958
As one of the world’s leading providers of distance learning astronomy study, UCLan offers a range of part-time courses starting from University Certifcates up to Honours Degree level. University Certifcates are single-module awards designed for people with no prior knowledge of the subject. They can be used towards more advanced awards leading to our BSc (Hons) Astronomy. Visit www.studyastronomy.com for more information.
UCLan’s BSc (Hons) and MPhys (Hons) Astrophysics, based at our well-appointed and modern campus in Preston, provide essential training in understanding the physical concepts that govern our Universe. Visit www.uclan.ac.uk/courses for more information.
01772 892400 enquiries@uclan.ac.uk www.studyastronomy.com
UnivERSiTY Of cEnTRal lancaSHiRE
pete
la
wre
nc
e
AprilSky Guide
The sky guide APRIL 51
skyatnightmagazine.com 2014
Mars reaches opposition this month. At this time, the planet will appear at its brightest and largest for the current period of observation. Located in the constellation of Virgo, a telescope will reveal tantalising details on this enigmatic world.
Written by Pete Lawrenceas well as writing The Sky Guide, pete can be seen on The Sky at Night on BBc Four. On page 64, he offers advice on how to avoid motion blur when imaging Mars with a mono high frame rate camera.
plusStephen Tonkin’s
BINOCULAR TOUR
Turn to page 62 for six of this month’s best
binocular sights
The
pete
la
wre
nc
e
AprilSky Guide
The sky guide APRIL 51
skyatnightmagazine.com 2014
Mars reaches opposition this month. At this time, the planet will appear at its brightest and largest for the current period of observation. Located in the constellation of Virgo, a telescope will reveal tantalising details on this enigmatic world.
Written by Pete Lawrenceas well as writing The Sky Guide, pete can be seen on The Sky at Night on BBc Four. On page 64, he offers advice on how to avoid motion blur when imaging Mars with a mono high frame rate camera.
plusStephen Tonkin’s
BINOCULAR TOUR
Turn to page 62 for six of this month’s best
binocular sights
The
52
Highlights
skyatnightmagazine.com 2014
pete
la
wre
nc
e x
8
this icon indicates a good photo opportunity
Your guide to the night sky this month
sunday the whirlpool
Galaxy, M51, is virtually overhead at midnight. this is a great opportunity to get better acquainted with this wonderful object.
27
monday
tonight’s full Moon
lies conveniently between Mars and mag. +1.0 Spica (alpha (a) Virginis). the star should stand out despite the Moon’s glare. Orange-hued Mars, shining at mag. –1.5, will be even more obvious above the Moon’s disc.
14Thursday
the bright star 5.5º to the north of the waxing gibbous
Moon (81% lit) is mag. +1.3 regulus (alpha (a) leonis). regulus should be easy to spot, but see if you can also pick out the fainter stars of the Sickle asterism, which extend above regulus in the shape of a backwards question mark.
10
wednesday
the dark Martian
feature known as the Syrtis Major is centrally located on the planet’s disc around midnight. a small telescope can show this V-shaped object well but, as is always the case with Mars, give your eye time to become accustomed to the view.
23
Tuesday
Mars comes to opposition in
Virgo. the planet has an apparent diameter of 15.1 arcseconds and the north polar cap should be fairly obvious through a telescope. around midnight, the dark V-shaped feature known as the Syrtis Major will be coming into view.
8
saTurday
the eta aquariid meteor shower becomes active
from now until 28 May. the peak zenithal hourly rate of this shower is typically 45 meteors per hour. peak activity occurs early next month, on 6 May.
19
saTurday
a lovely sight
awaits early risers: the waning crescent Moon (11% lit) lies close to brilliant Venus in the dawn twilight. look for the pair around 05:00 BSt (04:00 Ut); the Moon will appear to the left of Venus from the UK.
26
Thursday
the almost full Moon (96% lit)
is just 2.5º from Saturn this morning, low in the southwest. Both objects will be visible from around 22:30 BSt (21:30 Ut) on 16 april, with the Moon slowly but surely closing on the planet as dawn breaks.
17
Tuesday
the Moon’s crescent phase and libration make this a good time to view crater Humboldt, pictured. See page 63.
the best periods to take this month’s Deep-sky tour are from tonight until the 7th and from the 24th until the 30th. See page 60.
1
sunday
the waxing
crescent Moon (45% lit) will lie just 6º south of Jupiter this evening. at mag. –2.0 the planet will be obvious above the lunar disc.
6
52
Highlights
skyatnightmagazine.com 2014
pete
la
wre
nc
e x
8
this icon indicates a good photo opportunity
Your guide to the night sky this month
sunday the whirlpool
Galaxy, M51, is virtually overhead at midnight. this is a great opportunity to get better acquainted with this wonderful object.
27
monday
tonight’s full Moon
lies conveniently between Mars and mag. +1.0 Spica (alpha (a) Virginis). the star should stand out despite the Moon’s glare. Orange-hued Mars, shining at mag. –1.5, will be even more obvious above the Moon’s disc.
14Thursday
the bright star 5.5º to the north of the waxing gibbous
Moon (81% lit) is mag. +1.3 regulus (alpha (a) leonis). regulus should be easy to spot, but see if you can also pick out the fainter stars of the Sickle asterism, which extend above regulus in the shape of a backwards question mark.
10
wednesday
the dark Martian
feature known as the Syrtis Major is centrally located on the planet’s disc around midnight. a small telescope can show this V-shaped object well but, as is always the case with Mars, give your eye time to become accustomed to the view.
23
Tuesday
Mars comes to opposition in
Virgo. the planet has an apparent diameter of 15.1 arcseconds and the north polar cap should be fairly obvious through a telescope. around midnight, the dark V-shaped feature known as the Syrtis Major will be coming into view.
8
saTurday
the eta aquariid meteor shower becomes active
from now until 28 May. the peak zenithal hourly rate of this shower is typically 45 meteors per hour. peak activity occurs early next month, on 6 May.
19
saTurday
a lovely sight
awaits early risers: the waning crescent Moon (11% lit) lies close to brilliant Venus in the dawn twilight. look for the pair around 05:00 BSt (04:00 Ut); the Moon will appear to the left of Venus from the UK.
26
Thursday
the almost full Moon (96% lit)
is just 2.5º from Saturn this morning, low in the southwest. Both objects will be visible from around 22:30 BSt (21:30 Ut) on 16 april, with the Moon slowly but surely closing on the planet as dawn breaks.
17
Tuesday
the Moon’s crescent phase and libration make this a good time to view crater Humboldt, pictured. See page 63.
the best periods to take this month’s Deep-sky tour are from tonight until the 7th and from the 24th until the 30th. See page 60.
1
sunday
the waxing
crescent Moon (45% lit) will lie just 6º south of Jupiter this evening. at mag. –2.0 the planet will be obvious above the lunar disc.
6
The sky guide APRIL 53
skyatnightmagazine.com 2014
HoW To TeLL WHaT equiPmenT you’LL need
Getting started in astronomyIf you’re new to astronomy, you’ll find two essential reads on our website. Visit http://bit.ly/10_lessons for our 10-step guide to getting started and http://bit.ly/First_tel for advice on choosing your first scope.
naKed eyeAllow 20 minutes for your eyes to become dark-adapted
BinoCuLaRS10x50 recommended
SmaLL/medium SCoPeReflector/SCT under 6 inches, refractor under 4 inches
LaRGe SCoPeReflector/SCT over 6 inches, refractor over 4 inches
PHoTo oPPoRTuniTyUse a CCD, planetary camera or standard DSLR
need to knowThe terms and symbols used in The Sky Guide
univeRSaL Time (uT) and BRiTiSH SummeR Time (BST)Universal Time (UT) is the standard time used by astronomers around the world. British Summer Time (BST) is one hour ahead of UT.
Ra (RiGHT aSCenSion) and deC. (deCLinaTion) These coordinates are the night sky’s equivalent of longitude and latitude, describing where an object lies on the celestial ‘globe’.
Pete Lawrence “This month’s highlight has to be the planet Mars and I intend to catch it at every opportunity. I can’t wait to get outside and take some images of
this amazing planet.”
Chris Bramley “There are two sights I want to catch this month. The frst is the Syrtis Major on Mars; I'll also have a sunlounger and sleeping bag at the ready on the 22nd,
when the April Lyrid meteor shower peaks.”
Paul money “I’ll be tracking and photographing the motion of Ceres and Vesta as they come to opposition this month in Virgo, not far from Mars.”
what the team will be observing in april
wednesday
the familiar plough asterism
is virtually overhead around midnight. as the Moon is not around, this is a great time to investigate some of the deep-sky objects on offer in this area, such as the Owl nebula, shown right, and the lovely galaxy pair M81 and M82.
2
Tuesday
Dwarf planet ceres and
minor planet Vesta both come to opposition in Virgo. See page 54.
You may be able to see the start of the penumbral phase of a total lunar eclipse as the Moon sets at 06:00 BSt (05:00 Ut). See page 55.
15
Tuesday
tonight is the peak
of the annual lyrid meteor shower, which is active from 16-26 april. the normal peak zenithal hourly rate for this shower is 10 meteors per hour, but infrequent outbursts have been recorded. See page 55.
22monday
the enigmatically named realm of Galaxies is
due south at 23:30 BSt (22:30 Ut). located within the asterism known as the Bowl of Virgo, this area of the sky is rich in faint galaxies, many of which can be seen with a small telescope.
21
wednesday Keep an eye out
for a slender and rather beautiful waning crescent Moon just after sunset. Once the Sun has dipped below the horizon, keep an eye out for mag. –1.7 Mercury very low down in the west-northwest.
30
Thursday
the waxing crescent Moon
(18% lit) lies close to the Hyades open cluster in taurus this evening. look out for them around 21:30 BSt (20:30 Ut). the Moon should also be showing earthshine, which causes its dark portion to become dimly visible.
3
The sky guide APRIL 53
skyatnightmagazine.com 2014
HoW To TeLL WHaT equiPmenT you’LL need
Getting started in astronomyIf you’re new to astronomy, you’ll find two essential reads on our website. Visit http://bit.ly/10_lessons for our 10-step guide to getting started and http://bit.ly/First_tel for advice on choosing your first scope.
naKed eyeAllow 20 minutes for your eyes to become dark-adapted
BinoCuLaRS10x50 recommended
SmaLL/medium SCoPeReflector/SCT under 6 inches, refractor under 4 inches
LaRGe SCoPeReflector/SCT over 6 inches, refractor over 4 inches
PHoTo oPPoRTuniTyUse a CCD, planetary camera or standard DSLR
need to knowThe terms and symbols used in The Sky Guide
univeRSaL Time (uT) and BRiTiSH SummeR Time (BST)Universal Time (UT) is the standard time used by astronomers around the world. British Summer Time (BST) is one hour ahead of UT.
Ra (RiGHT aSCenSion) and deC. (deCLinaTion) These coordinates are the night sky’s equivalent of longitude and latitude, describing where an object lies on the celestial ‘globe’.
Pete Lawrence “This month’s highlight has to be the planet Mars and I intend to catch it at every opportunity. I can’t wait to get outside and take some images of
this amazing planet.”
Chris Bramley “There are two sights I want to catch this month. The frst is the Syrtis Major on Mars; I'll also have a sunlounger and sleeping bag at the ready on the 22nd,
when the April Lyrid meteor shower peaks.”
Paul money “I’ll be tracking and photographing the motion of Ceres and Vesta as they come to opposition this month in Virgo, not far from Mars.”
what the team will be observing in april
wednesday
the familiar plough asterism
is virtually overhead around midnight. as the Moon is not around, this is a great time to investigate some of the deep-sky objects on offer in this area, such as the Owl nebula, shown right, and the lovely galaxy pair M81 and M82.
2
Tuesday
Dwarf planet ceres and
minor planet Vesta both come to opposition in Virgo. See page 54.
You may be able to see the start of the penumbral phase of a total lunar eclipse as the Moon sets at 06:00 BSt (05:00 Ut). See page 55.
15
Tuesday
tonight is the peak
of the annual lyrid meteor shower, which is active from 16-26 april. the normal peak zenithal hourly rate for this shower is 10 meteors per hour, but infrequent outbursts have been recorded. See page 55.
22monday
the enigmatically named realm of Galaxies is
due south at 23:30 BSt (22:30 Ut). located within the asterism known as the Bowl of Virgo, this area of the sky is rich in faint galaxies, many of which can be seen with a small telescope.
21
wednesday Keep an eye out
for a slender and rather beautiful waning crescent Moon just after sunset. Once the Sun has dipped below the horizon, keep an eye out for mag. –1.7 Mercury very low down in the west-northwest.
30
Thursday
the waxing crescent Moon
(18% lit) lies close to the Hyades open cluster in taurus this evening. look out for them around 21:30 BSt (20:30 Ut). the Moon should also be showing earthshine, which causes its dark portion to become dimly visible.
3
54
skyatnightmagazine.com 2014
3 top sightsCeres and Vesta at opposition
NASA’S DAwN miSSioN is
approaching its second phase,
with the spacecraft getting ever
closer to dwarf planet Ceres.
Both Ceres and minor planet
Vesta – Dawn’s previous stop
– are in the same part of the sky
and enter opposition on the 15th.
Ceres was once the king of
the minor planets. with a
diameter of just under 1,000km,
it’s a body massive enough for
gravity to mould its shape into a
sphere. Ultimately this led to
Ceres being promoted from
minor planet to dwarf planet
back in 2006, at the same time
the international Astronomical
Union refned the defnitions of
what makes a planet ‘a planet’.
Dawn is due to reach Ceres
in spring 2015, so we should
know a lot more about this
amazing world next year.
Ceres starts the month at
mag. +7.1, making it an easy
binocular target. it brightens
by a tiny amount to mag. +7.0
around opposition on 15 April,
before dropping back to mag.
+7.1 again by the end of the
month. Throughout April it
moves from just north of mag.
+4.2 Tau (t) Virginis to a
position between mag. +5.4
84 Virginis and ffth-magnitude
variable star 78 Virginis.
Nearby is Vesta, a body with
a mean diameter just half that
of Ceres and classifed as a
minor planet. Despite being
smaller than Ceres, Vesta is
brighter; in fact the brightest of
all the minor planets. During
April its magnitude starts at
mag. +5.9, increases to mag.
+5.8 around opposition before
falling back to mag. +5.9 again.
This places Vesta just within
the bounds of naked-eye
visibility under dark skies. Like
Ceres, Vesta is also in Virgo
and appears to be travelling
along the same part of the sky.
At the start of the month, it
can be found just to the west of
Tau Virginis. it then heads on a
similar path to Ceres towards
78 Virginis, which it lies close
to by the end of April.
if you have clear skies and
a DSLR, these close encounters
will give you a great opportunity
to record the journeys. A 100mm
lens will produce an image
frame 12º across. Centre on
84 Virginis and take as many
shots as you can over the
course of the month. Load them
into a layer-based image editor
such as Photoshop or GimP as
separate layers, then align
common stars between frames.
Finally, set the blend mode of
all images, except the lowest
one, to ‘Lighten’. This should
reveal the passage of Ceres and
Vesta across the night sky.
pete
la
wre
nc
e x 4
WHen: all month
Ceres and vesta both pass 84 virginis during april, the star acting as a reference point to their progress
c
b
tCU
e
78
84
92
1 Apr
1 Apr11 Apr
11 Apr
21 Apr
21 Apr
1 May 1 May
Ceres
Vesta
1 Apr
15 AprMars
VIRGO
Heze
Auva
need To know!an object’s brightness is
given by its magnitude. the lower the number, the brighter the object: with the naked eye you can see down to mag. +6.0. at mag. +5.9 for much of the month, vesta is near naked-eye visibility
don’T
miss…
54
skyatnightmagazine.com 2014
3 top sightsCeres and Vesta at opposition
NASA’S DAwN miSSioN is
approaching its second phase,
with the spacecraft getting ever
closer to dwarf planet Ceres.
Both Ceres and minor planet
Vesta – Dawn’s previous stop
– are in the same part of the sky
and enter opposition on the 15th.
Ceres was once the king of
the minor planets. with a
diameter of just under 1,000km,
it’s a body massive enough for
gravity to mould its shape into a
sphere. Ultimately this led to
Ceres being promoted from
minor planet to dwarf planet
back in 2006, at the same time
the international Astronomical
Union refned the defnitions of
what makes a planet ‘a planet’.
Dawn is due to reach Ceres
in spring 2015, so we should
know a lot more about this
amazing world next year.
Ceres starts the month at
mag. +7.1, making it an easy
binocular target. it brightens
by a tiny amount to mag. +7.0
around opposition on 15 April,
before dropping back to mag.
+7.1 again by the end of the
month. Throughout April it
moves from just north of mag.
+4.2 Tau (t) Virginis to a
position between mag. +5.4
84 Virginis and ffth-magnitude
variable star 78 Virginis.
Nearby is Vesta, a body with
a mean diameter just half that
of Ceres and classifed as a
minor planet. Despite being
smaller than Ceres, Vesta is
brighter; in fact the brightest of
all the minor planets. During
April its magnitude starts at
mag. +5.9, increases to mag.
+5.8 around opposition before
falling back to mag. +5.9 again.
This places Vesta just within
the bounds of naked-eye
visibility under dark skies. Like
Ceres, Vesta is also in Virgo
and appears to be travelling
along the same part of the sky.
At the start of the month, it
can be found just to the west of
Tau Virginis. it then heads on a
similar path to Ceres towards
78 Virginis, which it lies close
to by the end of April.
if you have clear skies and
a DSLR, these close encounters
will give you a great opportunity
to record the journeys. A 100mm
lens will produce an image
frame 12º across. Centre on
84 Virginis and take as many
shots as you can over the
course of the month. Load them
into a layer-based image editor
such as Photoshop or GimP as
separate layers, then align
common stars between frames.
Finally, set the blend mode of
all images, except the lowest
one, to ‘Lighten’. This should
reveal the passage of Ceres and
Vesta across the night sky.
pete
la
wre
nc
e x 4
WHen: all month
Ceres and vesta both pass 84 virginis during april, the star acting as a reference point to their progress
c
b
tCU
e
78
84
92
1 Apr
1 Apr11 Apr
11 Apr
21 Apr
21 Apr
1 May 1 May
Ceres
Vesta
1 Apr
15 AprMars
VIRGO
Heze
Auva
need To know!an object’s brightness is
given by its magnitude. the lower the number, the brighter the object: with the naked eye you can see down to mag. +6.0. at mag. +5.9 for much of the month, vesta is near naked-eye visibility
don’T
miss…
skyatnightmagazine.com 2014
The sky guide APRIL 55
The April lyrids are one
of the regular annual meteor
showers and a welcome break
from the relatively sparse period
of meteor activity that occurs
at the start of the year. The
shower is active from 16-26
April, peaking on the 22nd.
The Moon is going to
interfere at the start of this
period, being fractionally past
full on the night of the 16th,
rising at 21:50 BsT (20:50 UT).
however, over the next few days
the Moon’s decrease in phase,
coupled with it slipping
farther to the south and east
in the sky, will aid meteor
visibility. The Moon is absent
from the evening sky on the
22nd; it rises at around 03:15
BsT (02:15 UT) on the 23rd,
when it will show a waning
crescent (41% lit) phase.
The April lyrids typically
show a peak of around 10
meteors per hour. This is the
zenithal hourly rate – the
value that indicates the
number of meteors you’d see
if the shower radiant, where
the meteors appear to emanate
from, were directly overhead.
The zenithal hourly rate
fgure is only a guide, however,
as it assumes perfect skies and
the fact that you can see the
entire sky in one go – which
unfortunately you can’t!
Consequently, the visually
observed rate will be lower.
The April lyrids are a result
of earth passing through the
dust stream spread along the
orbit of comet C/1861 G1
Thatcher. its meteors appear
to emanate from a location
slightly off to the west of mag.
0.0 Vega (Alpha (a) lyrae),
with an average trail
brightness of mag. +2.0.
Outbursts from the April
A ToTAL LUNAR eclipse
takes place on 15 April.
Unfortunately the main part
occurs after the moon has set
for observers in the UK, but
you may be able to catch the
beginning of the event.
The main, dark part of the
shadow, known as the umbra,
begins to cross the lunar disc
at 06:58 BST (05:58 UT), by
which point the moon will be
no longer visible from the UK.
But we should be able to see
the fainter, outer part of
Earth’s shadow, known as the
penumbra, begin to encroach
on the lunar disc.
The penumbra frst starts
to cross the edge of the moon
at 05:53 BST (04:53 UT), when
the moon is still 2º above the
UK’s west-southwest horizon.
whether we get to see any
hint of shading from the
penumbral part of the eclipse
can’t be predicted with
certainty, but it’s always worth
going out to have a look.
Locate the full moon at
05:30 BST (04:30 UT) and you
should see bright mars off to
the right and fainter, mag.
+1.0 Spica (Alpha (a)
Virginis), just 1º from the
moon’s centre, off to the lower
left. As the moon gets closer
to the horizon it will be nicely
located in the Belt of Venus
– the projection of the closer
part of Earth’s shadow in the
atmosphere.
lyrids occur roughly every 60
years, with 700 meteors per hour
recorded in 1803. sadly, the
last one was in 1982, so we’re
not expecting to see anything
out of the ordinary this time.
The shower radiant lies between the Summer Triangle and Keystone asterisms
Summer Triangle
CYGNUS
Deneb
Vega
Altair
Keystone
LYRA
VULPECULA
SAGITTA
AQUILA
DELPHINUS
HERCULES
April LyridsRadiant
15 Apr
25 Apr
20 Apr
22 Apr
Total lunar eclipse
The orionids peak on 21 october, but you’ll have to
contend with a bright moon
need To know!the planets of the Solar
System occupy similar orbital planes; it is this ‘co-planar’ nature that allows us to see conjunctions from our perspective on earth.
mag. +1.0 Spica sits below and left of the moon as the eclipse begins
WHen: From 05:30 BST (04:30 uT) on 15 april
April Lyrid meteor shower WHen: 16-26 april; peak occurs on the 22nd
skyatnightmagazine.com 2014
The sky guide APRIL 55
The April lyrids are one
of the regular annual meteor
showers and a welcome break
from the relatively sparse period
of meteor activity that occurs
at the start of the year. The
shower is active from 16-26
April, peaking on the 22nd.
The Moon is going to
interfere at the start of this
period, being fractionally past
full on the night of the 16th,
rising at 21:50 BsT (20:50 UT).
however, over the next few days
the Moon’s decrease in phase,
coupled with it slipping
farther to the south and east
in the sky, will aid meteor
visibility. The Moon is absent
from the evening sky on the
22nd; it rises at around 03:15
BsT (02:15 UT) on the 23rd,
when it will show a waning
crescent (41% lit) phase.
The April lyrids typically
show a peak of around 10
meteors per hour. This is the
zenithal hourly rate – the
value that indicates the
number of meteors you’d see
if the shower radiant, where
the meteors appear to emanate
from, were directly overhead.
The zenithal hourly rate
fgure is only a guide, however,
as it assumes perfect skies and
the fact that you can see the
entire sky in one go – which
unfortunately you can’t!
Consequently, the visually
observed rate will be lower.
The April lyrids are a result
of earth passing through the
dust stream spread along the
orbit of comet C/1861 G1
Thatcher. its meteors appear
to emanate from a location
slightly off to the west of mag.
0.0 Vega (Alpha (a) lyrae),
with an average trail
brightness of mag. +2.0.
Outbursts from the April
A ToTAL LUNAR eclipse
takes place on 15 April.
Unfortunately the main part
occurs after the moon has set
for observers in the UK, but
you may be able to catch the
beginning of the event.
The main, dark part of the
shadow, known as the umbra,
begins to cross the lunar disc
at 06:58 BST (05:58 UT), by
which point the moon will be
no longer visible from the UK.
But we should be able to see
the fainter, outer part of
Earth’s shadow, known as the
penumbra, begin to encroach
on the lunar disc.
The penumbra frst starts
to cross the edge of the moon
at 05:53 BST (04:53 UT), when
the moon is still 2º above the
UK’s west-southwest horizon.
whether we get to see any
hint of shading from the
penumbral part of the eclipse
can’t be predicted with
certainty, but it’s always worth
going out to have a look.
Locate the full moon at
05:30 BST (04:30 UT) and you
should see bright mars off to
the right and fainter, mag.
+1.0 Spica (Alpha (a)
Virginis), just 1º from the
moon’s centre, off to the lower
left. As the moon gets closer
to the horizon it will be nicely
located in the Belt of Venus
– the projection of the closer
part of Earth’s shadow in the
atmosphere.
lyrids occur roughly every 60
years, with 700 meteors per hour
recorded in 1803. sadly, the
last one was in 1982, so we’re
not expecting to see anything
out of the ordinary this time.
The shower radiant lies between the Summer Triangle and Keystone asterisms
Summer Triangle
CYGNUS
Deneb
Vega
Altair
Keystone
LYRA
VULPECULA
SAGITTA
AQUILA
DELPHINUS
HERCULES
April LyridsRadiant
15 Apr
25 Apr
20 Apr
22 Apr
Total lunar eclipse
The orionids peak on 21 october, but you’ll have to
contend with a bright moon
need To know!the planets of the Solar
System occupy similar orbital planes; it is this ‘co-planar’ nature that allows us to see conjunctions from our perspective on earth.
mag. +1.0 Spica sits below and left of the moon as the eclipse begins
WHen: From 05:30 BST (04:30 uT) on 15 april
April Lyrid meteor shower WHen: 16-26 april; peak occurs on the 22nd
BOÖTESArcturus
VIRGO
CORVUS
Spica
Porrima
Heze
Vindemiatrix
Zavijava
LEO
Mars30th
1st
`
¡
`
g
a
a
b
d
c
56
skyatnightmagazine.com 2014
mARS REAChES oPPoSiTioN on
8 April and is visible all night long. on
this date the planet will be in the opposite
part of the sky to the Sun and appear
at its brightest for the current
period of observation
at mag. –1.5.
At the start of
the month mars
appears to be 14.7
arcseconds across
when viewed
through a
telescope. At this
scale, a small scope
should be capable of
revealing the main
markings on the planet,
such as the V-shaped Syrtis
major. The ‘V’ description only
really works in an inverted
telescopic view as the tip of the
The phase, tilt and relative sizes of the planets in April. Each planet is shown with south at the top, to show what it looks like through a telescope
How the planets will appear this month
maRS 15 apr
JuPiTeR 15 apr
SaTuRn 15 apr
uRanuS 15 apr
noT viSiBLe
aRCSeCondS
0” 10” 20” 30” 40” 50” 1’
pete l
aw
ren
ce x
2
The planets
‘V’ points north. we’ve indicated a
couple of times to look out for
the Syrtis major in this
month’s highlights
calendar on pages
52-53. it is just one
of several features
that appear dark
against mars’s
lighter deserts.
Roughly four
and a half hours
after the Syrtis major
is on the centreline of
the planet’s disc, a
smaller two-pronged feature
comes into view; one of the
prongs is known as the Sinus
meridiani. This feature marks
the martian equivalent of the Greenwich
meridian on the martian globe. Another
(this time bright) feature that should be
fairly easy to spot with a small telescope is
the planet’s north polar cap.
mars continues to get closer to Earth
and so appear larger through a telescope
for about a week following opposition. on
the 15th the planet achieves an apparent
diameter of 15.2 arcseconds. Though this
is not much more than that shown on the
8th, where mars is concerned every little
bit is most welcome.
At the end of the month, mars is mag.
–1.2, has an apparent diameter of 14.6
arcseconds and sits 1.5º from mag. +3.4
Porrima (Gamma (g) Virginis). For more
tips on observing mars at opposition, turn
to our in-depth feature on page 41.
MARs
BeST Time in aPRiL: 8 April, 01:22 BST (00:22 UT) aLTiTude: 31º LoCaTion: Virgo
diReCTion: SouthReCommended equiPmenT: 6-inch or larger telescopeFeaTuReS oF inTeReST: Polar caps, dark markings, clouds and dust storms.
venuS 15 apr
meRCuRy 15 apr
mars stays in virgo throughout april; it won’t be hard to find, blazing away at a brilliant mag. –1.5
meRCuRy 1 apr
mars’s north polar cap should be an easy spot
nePTune 15 apr
noT viSiBLe
Pick of The monTh
meRCuRy 30 apr
BOÖTESArcturus
VIRGO
CORVUS
Spica
Porrima
Heze
Vindemiatrix
Zavijava
LEO
Mars30th
1st
`
¡
`
g
a
a
b
d
c
56
skyatnightmagazine.com 2014
mARS REAChES oPPoSiTioN on
8 April and is visible all night long. on
this date the planet will be in the opposite
part of the sky to the Sun and appear
at its brightest for the current
period of observation
at mag. –1.5.
At the start of
the month mars
appears to be 14.7
arcseconds across
when viewed
through a
telescope. At this
scale, a small scope
should be capable of
revealing the main
markings on the planet,
such as the V-shaped Syrtis
major. The ‘V’ description only
really works in an inverted
telescopic view as the tip of the
The phase, tilt and relative sizes of the planets in April. Each planet is shown with south at the top, to show what it looks like through a telescope
How the planets will appear this month
maRS 15 apr
JuPiTeR 15 apr
SaTuRn 15 apr
uRanuS 15 apr
noT viSiBLe
aRCSeCondS
0” 10” 20” 30” 40” 50” 1’
pete l
aw
ren
ce x
2
The planets
‘V’ points north. we’ve indicated a
couple of times to look out for
the Syrtis major in this
month’s highlights
calendar on pages
52-53. it is just one
of several features
that appear dark
against mars’s
lighter deserts.
Roughly four
and a half hours
after the Syrtis major
is on the centreline of
the planet’s disc, a
smaller two-pronged feature
comes into view; one of the
prongs is known as the Sinus
meridiani. This feature marks
the martian equivalent of the Greenwich
meridian on the martian globe. Another
(this time bright) feature that should be
fairly easy to spot with a small telescope is
the planet’s north polar cap.
mars continues to get closer to Earth
and so appear larger through a telescope
for about a week following opposition. on
the 15th the planet achieves an apparent
diameter of 15.2 arcseconds. Though this
is not much more than that shown on the
8th, where mars is concerned every little
bit is most welcome.
At the end of the month, mars is mag.
–1.2, has an apparent diameter of 14.6
arcseconds and sits 1.5º from mag. +3.4
Porrima (Gamma (g) Virginis). For more
tips on observing mars at opposition, turn
to our in-depth feature on page 41.
MARs
BeST Time in aPRiL: 8 April, 01:22 BST (00:22 UT) aLTiTude: 31º LoCaTion: Virgo
diReCTion: SouthReCommended equiPmenT: 6-inch or larger telescopeFeaTuReS oF inTeReST: Polar caps, dark markings, clouds and dust storms.
venuS 15 apr
meRCuRy 15 apr
mars stays in virgo throughout april; it won’t be hard to find, blazing away at a brilliant mag. –1.5
meRCuRy 1 apr
mars’s north polar cap should be an easy spot
nePTune 15 apr
noT viSiBLe
Pick of The monTh
meRCuRy 30 apr
MeRCURy BeST Time in aPRiL: 30 April, 21:00 BST (20:00 UT) aLTiTude: 1º (low)LoCaTion: AriesdiReCTion: West-northwestmercury spends most of the
month poorly placed in the
morning sky, with both planet
and Sun rising at approximately
the same time. Superior
conjunction occurs on the 26th
and the prospects for spotting
mercury in the evening sky are
much better. See if you can catch
a glimpse of the mag. –1.7
planet very low on the west-
northwest horizon shortly after
sunset at the end of the month.
VeNUs BeST Time in aPRiL: 25 and 26 April, 05:20 BST (04:20 UT)aLTiTude: 5º (low)LoCaTion: AquariusdiReCTion: EastVenus is a morning object that
shines brighter than mag. –4.0
all month. Despite this, the
planet’s aspect as seen from
the UK is worsening; it’s quite
low in the dawn twilight prior
to sunrise. A telescope will
now show its disc to have a
gibbous phase. At the start
of April, Venus appears to be
22 arcseconds across with a
phase of 54%. By month end,
this will have changed to
17 arcseconds and a phase of
66%. Look out for attractive
conjunctions between Venus
and the waning crescent moon
in the east-southeast dawn sky
on the 25th and 26th.
JUpITeR BeST Time in aPRiL: 1 April, 21:30 BST (20:30 UT)aLTiTude: 52º LoCaTion: GeminidiReCTion: SouthwestJupiter is best seen at the start
of April, when its impressive
mag. –1.2 dot can be seen 52º
up in the southwest as the
sky darkens. At the start of
April the planet shows a
38-arcsecond disc when
viewed through a telescope,
plenty big enough to show
some great detail even with
small instruments. on the
6th, the waxing crescent
moon (45% lit) lies 6º below
the planet. By the end of the
month, the distance between
us and Jupiter will have
increased, resulting in the
planet appearing slightly
smaller at 35 arcseconds
across, and slightly fainter at
mag. –1.9. The planet remains
in Gemini all month.
sATURN BeST Time in aPRiL: 30 April, 02:00 BST (01:00 UT) aLTiTude: 21º LoCaTion: LibradiReCTion: SouthSitting in the constellation
of Libra, Saturn doesn’t get
very high above the UK’s
southern horizon, even when
due south. Don’t let that deter
you though. if you have a
telescope, it’s defnitely worth
trying to get a view of this
beautiful planet.
At the start of April, Saturn
is mag. +0.6 and its disc
appears to be 18 arcseconds
across. it rises at 22:30 BST
(21:30 UT) on the 1st and
manages to reach its highest
point in the sky, 21º up and
due south, in darkness. The
almost full moon lies just
2º from Saturn in the early
hours of 17 April. Look out
for the pair low in the
southwest at around 05:30
BST (04:30 UT). At the end
of the month, Saturn is
visible all night long and
this is the best time to try
and get a view of it.
NOT VISIBLE THIS MONTHURANUs, NepTUNe
AprilUsing a small scope you’ll be able to spot Saturn’s biggest moons. their positions change dramatically during the month, as shown on the diagram. the line by each date on the left represents midnight.
SaT u R n ’S m o o nS
arcminutes
DATE WEST EAST
3210123
2
1
3
5
4
6
8
7
9
11
10
12
14
13
15
17
16
18
20
19
21
23
22
24
25
26
28
27
29
30
1
Dione Rhea TitanTethys Iapetus Saturn
See what the planets look like through your telescope with the feld of view calculator on our website at:
http://www.skyatnightmagazine.com/astronomy-tools
MeRCURy BeST Time in aPRiL: 30 April, 21:00 BST (20:00 UT) aLTiTude: 1º (low)LoCaTion: AriesdiReCTion: West-northwestmercury spends most of the
month poorly placed in the
morning sky, with both planet
and Sun rising at approximately
the same time. Superior
conjunction occurs on the 26th
and the prospects for spotting
mercury in the evening sky are
much better. See if you can catch
a glimpse of the mag. –1.7
planet very low on the west-
northwest horizon shortly after
sunset at the end of the month.
VeNUs BeST Time in aPRiL: 25 and 26 April, 05:20 BST (04:20 UT)aLTiTude: 5º (low)LoCaTion: AquariusdiReCTion: EastVenus is a morning object that
shines brighter than mag. –4.0
all month. Despite this, the
planet’s aspect as seen from
the UK is worsening; it’s quite
low in the dawn twilight prior
to sunrise. A telescope will
now show its disc to have a
gibbous phase. At the start
of April, Venus appears to be
22 arcseconds across with a
phase of 54%. By month end,
this will have changed to
17 arcseconds and a phase of
66%. Look out for attractive
conjunctions between Venus
and the waning crescent moon
in the east-southeast dawn sky
on the 25th and 26th.
JUpITeR BeST Time in aPRiL: 1 April, 21:30 BST (20:30 UT)aLTiTude: 52º LoCaTion: GeminidiReCTion: SouthwestJupiter is best seen at the start
of April, when its impressive
mag. –1.2 dot can be seen 52º
up in the southwest as the
sky darkens. At the start of
April the planet shows a
38-arcsecond disc when
viewed through a telescope,
plenty big enough to show
some great detail even with
small instruments. on the
6th, the waxing crescent
moon (45% lit) lies 6º below
the planet. By the end of the
month, the distance between
us and Jupiter will have
increased, resulting in the
planet appearing slightly
smaller at 35 arcseconds
across, and slightly fainter at
mag. –1.9. The planet remains
in Gemini all month.
sATURN BeST Time in aPRiL: 30 April, 02:00 BST (01:00 UT) aLTiTude: 21º LoCaTion: LibradiReCTion: SouthSitting in the constellation
of Libra, Saturn doesn’t get
very high above the UK’s
southern horizon, even when
due south. Don’t let that deter
you though. if you have a
telescope, it’s defnitely worth
trying to get a view of this
beautiful planet.
At the start of April, Saturn
is mag. +0.6 and its disc
appears to be 18 arcseconds
across. it rises at 22:30 BST
(21:30 UT) on the 1st and
manages to reach its highest
point in the sky, 21º up and
due south, in darkness. The
almost full moon lies just
2º from Saturn in the early
hours of 17 April. Look out
for the pair low in the
southwest at around 05:30
BST (04:30 UT). At the end
of the month, Saturn is
visible all night long and
this is the best time to try
and get a view of it.
NOT VISIBLE THIS MONTHURANUs, NepTUNe
AprilUsing a small scope you’ll be able to spot Saturn’s biggest moons. their positions change dramatically during the month, as shown on the diagram. the line by each date on the left represents midnight.
SaT u R n ’S m o o nS
arcminutes
DATE WEST EAST
3210123
2
1
3
5
4
6
8
7
9
11
10
12
14
13
15
17
16
18
20
19
21
23
22
24
25
26
28
27
29
30
1
Dione Rhea TitanTethys Iapetus Saturn
See what the planets look like through your telescope with the feld of view calculator on our website at:
http://www.skyatnightmagazine.com/astronomy-tools
skyatnightmagazine.com 2014
The Northern Hemisphere
monday tuesday wednesday thursday friday saturday sunday
Summ
er Triangle
Keystone
Northern Cross
R
39
M13
M92
M57
M5
HERCULES
CYGN
US
CORO
NA
BOREALIS
SERPE
NS CAPU
T
LYRA
OPHIUCHUS
LIBRA
α
β
γ
αβ
γδ
γ
β
αβγ
α
β
γ
δ
α
α
γβ
δ
α
δ
γβ
δ
β
δ Oph
η
ζ
Deneb
Vega
Rasalgethi
Rasalhague
Albireo
Saturn
April LyridsPeaks 22 April
16th
Deep
-sky
tour, p
57
NORTHEAST
EA
ST
SOUTHEAST
HOW to use this chart1. hold the chart so the direction you’re facing
is at the bottom.2. the lower half of the chart shows the sky
ahead of you.3. the centre of the chart is the point
directly over your head.
THe Sun in aPril*
*times correct for the centre of the uK
date sunrise sunset01 apr 2014 06:43 Bst 19:45 Bst
11 apr 2014 06:20 Bst 20:03 Bst
21 apr 2014 05:57 Bst 20:21 Bst
01 may 2014 05:35 Bst 20:39 Bst
moonrise times01 apr 2014, 07:23 Bst 17 apr 2014, 23:02 Bst
05 apr 2014, 09:58 Bst 21 apr 2014, 01:54 Bst
09 apr 2014, 13:51 Bst 25 apr 2014, 04:05 Bst
13 apr 2014, 18:17 Bst 29 apr 2014, 05:52 Bst
THe MOOn in aPril*
1 aPril at 01:00 Bst 15 aPril at 00:00 Bst30 aPril at 23:00 BstOn other dates, use the interactive planetarium on our website at www.skyatnightmagazine.com/interactive-planetarium
WHen to use this chart
1 2 3 4 5 6
7 8 9 10 11 12 13
14 15 16 17 18 19 20
21 22 23 24 25 26 27
28 29 30
fuLL moon
new moon
58
PERSEUS
Arcturus
Circlet
N
E
S
W
5º
STAR NAME
CONSTELLATION
NAME
GALAXY
OPEN CLUSTER
GLOBULAR
CLUSTER
PLANETARY
NEBULA
DIFFUSE
NEBULOSITY
DOUBLE STAR
VARIABLE STAR
THE MOON,
SHOWING PHASE
COMET TRACK
ASTEROID
TRACK
STAR-HOPPING
PATH
METEOR
RADIANT
ASTERISM
PLANET
QUASAR
STAR BRIGHTNESS:
MAG. 0
& BRIGHTER
MAG. +1
MAG. +2
MAG. +3
MAG. +4
& FAINTER
MILKY WAY
COMPASS AND
FIELD OF VIEW
Key to
star charts
skyatnightmagazine.com 2014
The Northern Hemisphere
monday tuesday wednesday thursday friday saturday sunday
Summ
er Triangle
Keystone
Northern Cross
R
39
M13
M92
M57
M5
HERCULES
CYGN
US
CORO
NA
BOREALIS
SERPE
NS CAPU
T
LYRA
OPHIUCHUS
LIBRA
α
β
γ
αβ
γδ
γ
β
αβγ
α
β
γ
δ
α
α
γβ
δ
α
δ
γβ
δ
β
δ Oph
η
ζ
Deneb
Vega
Rasalgethi
Rasalhague
Albireo
Saturn
April LyridsPeaks 22 April
16th
Deep
-sky
tour, p
57
NORTHEAST
EA
ST
SOUTHEAST
HOW to use this chart1. hold the chart so the direction you’re facing
is at the bottom.2. the lower half of the chart shows the sky
ahead of you.3. the centre of the chart is the point
directly over your head.
THe Sun in aPril*
*times correct for the centre of the uK
date sunrise sunset01 apr 2014 06:43 Bst 19:45 Bst
11 apr 2014 06:20 Bst 20:03 Bst
21 apr 2014 05:57 Bst 20:21 Bst
01 may 2014 05:35 Bst 20:39 Bst
moonrise times01 apr 2014, 07:23 Bst 17 apr 2014, 23:02 Bst
05 apr 2014, 09:58 Bst 21 apr 2014, 01:54 Bst
09 apr 2014, 13:51 Bst 25 apr 2014, 04:05 Bst
13 apr 2014, 18:17 Bst 29 apr 2014, 05:52 Bst
THe MOOn in aPril*
1 aPril at 01:00 Bst 15 aPril at 00:00 Bst30 aPril at 23:00 BstOn other dates, use the interactive planetarium on our website at www.skyatnightmagazine.com/interactive-planetarium
WHen to use this chart
1 2 3 4 5 6
7 8 9 10 11 12 13
14 15 16 17 18 19 20
21 22 23 24 25 26 27
28 29 30
fuLL moon
new moon
58
PERSEUS
Arcturus
Circlet
N
E
S
W
5º
STAR NAME
CONSTELLATION
NAME
GALAXY
OPEN CLUSTER
GLOBULAR
CLUSTER
PLANETARY
NEBULA
DIFFUSE
NEBULOSITY
DOUBLE STAR
VARIABLE STAR
THE MOON,
SHOWING PHASE
COMET TRACK
ASTEROID
TRACK
STAR-HOPPING
PATH
METEOR
RADIANT
ASTERISM
PLANET
QUASAR
STAR BRIGHTNESS:
MAG. 0
& BRIGHTER
MAG. +1
MAG. +2
MAG. +3
MAG. +4
& FAINTER
MILKY WAY
COMPASS AND
FIELD OF VIEW
Key to
star charts
Celesti
al Equa
torEclip
tic
Kite
House
W
Sick
le
Plough
U
RR
X
T
S
R
X
U
M39
M51
M103
M52
Dou
ble
Clu
ster
M34
M81
M82
M101
M38
M36
M37
M35
M44
M67
M63
M65
M66
M53
M64
M96 M
48
M94
M3
M102
M61
M49
M60
M90
M91 M88
M10
5
M95
M58
M84M86
M98M99
M100
M59
M87
M104
URSAMAJOR
DRA
CO
URSA
MIN
OR
CEPHEUS
ANDROMEDA
CASSIOPEIA PERSEU
S
CA
MEL
OPA
RDA
LIS
AU
RIG
A
LYN
X
GEMINI
CANCER
CA
NIS
MIN
OR
LEO
LEO M
INOR
MO
NO
CER
OS
HYDR
A
SEXTANS
CANESVENATICI
COMA
BERENICES
VIRGO
BOÖTE
S
CRATER
CORVUS
NA
S
ORI
ON
ANTILA
LACERTA
TAU
RUS
γ
α
βδ
ε
β
α
γ
δ
α
β
γ
δ
α
ι
α
δ
β
γ
α
β
γ
δ
αβ
α
β
α
β γ
β
α
α
β
γδ
α
β
γ
δ
α
α
αβ
α
β
γ
δ
α
β
δ
γ
α
β
δ
α β
β
γ
α
β
α
βγ
δ
α
β γ
δ
α
β
δα
α
β
γδ
γ
δ
β
ι
μ
θ
ν
ρ
Thuban
Kochab
Polaris
Schedar
Mirp
hak
Algol
Cape
lla
Dubhe
MerakMizar
Alcor
Cor CaroliA
lderamin
Casto
r
Pollux
Elna
th
Kids
Proc
yon
Regulus
Den
ebol
a
Alph
ard
Porrima
Arcturu
s
Spica
Vindemiatrix
Jupite
r
Mars1st 30th
April Virginids
PeakS 11 April
Gamma Virginids
Peaks 14 April
7th
13th
10th
16th
NORTH
SOUTH
SOUTH
WES
T
WES
T
N
ORTHW
EST
the sky guide APRIL 59
skyatnightmagazine.com 2014
Celesti
al Equa
torEclip
tic
Kite
House
W
Sick
le
Plough
U
RR
X
T
S
R
X
U
M39
M51
M103
M52
Dou
ble
Clu
ster
M34
M81
M82
M101
M38
M36
M37
M35
M44
M67
M63
M65
M66
M53
M64
M96 M
48
M94
M3
M102
M61
M49
M60
M90
M91 M88
M10
5
M95
M58
M84M86
M98M99
M100
M59
M87
M104
URSAMAJOR
DRA
CO
URSA
MIN
OR
CEPHEUS
ANDROMEDA
CASSIOPEIA PERSEU
S
CA
MEL
OPA
RDA
LIS
AU
RIG
A
LYN
X
GEMINI
CANCER
CA
NIS
MIN
OR
LEO
LEO M
INOR
MO
NO
CER
OS
HYDR
A
SEXTANS
CANESVENATICI
COMA
BERENICES
VIRGO
BOÖTE
S
CRATER
CORVUS
NA
S
ORI
ON
ANTILALACERTA
TAU
RUS
γ
α
βδ
ε
β
α
γ
δ
α
β
γ
δ
α
ι
α
δ
β
γ
α
β
γ
δ
αβ
α
β
α
β γ
β
α
α
β
γδ
α
β
γ
δ
α
α
αβ
α
β
γ
δ
α
β
δ
γ
α
β
δ
α β
β
γ
α
β
α
βγ
δ
α
β γ
δ
α
β
δα
α
β
γδ
γ
δ
β
ι
μ
θ
ν
ρ
Thuban
Kochab
Polaris
Schedar
Mirp
hak
Algol
Cape
lla
Dubhe
MerakMizar
Alcor
Cor Caroli
Alderam
in
Casto
r
Pollux
Elna
th
Kids
Proc
yon
Regulus
Den
ebol
a
Alph
ard
Porrima
Arcturu
s
Spica
Vindemiatrix
Jupite
r
Mars1st 30th
April Virginids
PeakS 11 April
Gamma Virginids
Peaks 14 April
7th
13th
10th
16th
NORTH
SOUTH
SOUTH
WES
T
WES
T
N
ORTHW
EST
the sky guide APRIL 59
skyatnightmagazine.com 2014
60
skyatnightmagazine.com 2014
M5 Our first port of call this month is the rather wonderful globular cluster known as M5.
Located within the constellation of Serpens Caput, quite close to the border with Virgo, M5’s appearance through an eyepiece is on a par with better-known M13 in Hercules. A small scope shows M5 to be condensed, with a hint of star resolution at the edges. A 6-inch telescope at 200x magnification should be capable of resolving the cluster to the core, revealing many distinctive ‘strings’ of stars. This is one of the oldest globular clusters known with an estimated age of 13 billion years. SEEN IT
PaloMar 5 Our next target is also a globular cluster, but this one is at the other end of the brightness
scale. Known as Palomar 5, this globular appears as little more than a smudge of light, and as such is best seen with large aperture scopes or via imaging. It has magnitude of +11.8 but is spread out, so its surface brightness is low. Find it 2.3º to the southwest of M5. The cluster is being disrupted by the gravitation of the Milky Way and there is evidence of streams of stars leaving it. For a while it was thought to be a dwarf galaxy. SEEN ITC
HA
rT A
nd
PH
OTO
: Pe
Te L
AW
ren
Ce
There’s much more to see in the skies around Libra than the ringed wonder of Saturn
Tick the box when you’ve seen each one ✓
Deep-sky tour
-20
ZubENESchaMalI Continue south from Palomar 5 and you’ll reach the constellation of Libra and our next
target – mag. +2.6 Zubeneschamali (Beta (β) Librae). This star is distinct because of reports that it appears to have a green tint. If true, this makes it the only greenish star in the sky visible to the naked eye. A star with peak output in the green part of the spectrum also emits blue and red light. Consequently, our eyes fail to see just green. So does Zubeneschamali actually look green? The only way to tell is to take a look yourself. SEEN IT
NGc 5897 One of the few deep-sky objects in the heart of Libra is globular cluster nGC 5897 – look
for it 1.5º southeast of mag. +4.5 Iota (ι) Librae. nGC 5897 is a broad, diffuse globular that can only be partially resolved, but at mag. +8.6 is considerably easier to identify than Palomar 5. The core looks quite uniform in brightness with no obvious central condensation. Brighter core stars can be made out individually, but the many fainter members merge together like a nebulous haze. There is a notable triple pattern of mag. +11.5 to mag. +13.5 stars located north-northwest of the cluster’s centre. SEEN IT
MErrIll 2-1 There’s another challenging object located 3º to the southeast of nGC 5897, a mag. +11.6
planetary nebula known as Merrill 2-1. This is a tricky spot: the nebula is relatively faint, quite small and located extremely close to a mag. +11.2 star. There’s a mag. +9.9 star designated SAO 183407 50 arcseconds to the west that serves as a good pointer to the area. Once you’ve found the nebula and its close mag. +11.2 star, don’t be afraid to pile on the magnification. At 150x magnification the nebula will start to look like a slightly blurred star. A 6- to 8-inch scope at 200x magnification is needed to show it convincingly. SEEN IT
18 lIbraE Our final object is double star 18 Librae. The primary star is a mag. +5.9 orange
giant that lies 316 lightyears from the Sun. It is fairly easy to locate, being the third point in a squat isosceles triangle that also includes Zubeneschamali (our third stop) and mag. +2.8 Zubenelgenubi (Alpha (α) Librae); the slightly brighter mag. +5.8 Xi1 (ξ1) and mag. +5.5 Xi2 (ξ2) Librae also point toward it. A small scope will reveal that the orange giant has a yellow, mag. +9.9 companion 19.7 arcseconds away. Also look out for a third, mag. +11.5 star 162 arcseconds to the northeast of the primary. SEEN IT
If you have a large scope, look for the ‘strings’ of stars
streaming from M5’s core
2
3
4
5
6
1
60
skyatnightmagazine.com 2014
M5 Our first port of call this month is the rather wonderful globular cluster known as M5.
Located within the constellation of Serpens Caput, quite close to the border with Virgo, M5’s appearance through an eyepiece is on a par with better-known M13 in Hercules. A small scope shows M5 to be condensed, with a hint of star resolution at the edges. A 6-inch telescope at 200x magnification should be capable of resolving the cluster to the core, revealing many distinctive ‘strings’ of stars. This is one of the oldest globular clusters known with an estimated age of 13 billion years. SEEN IT
PaloMar 5 Our next target is also a globular cluster, but this one is at the other end of the brightness
scale. Known as Palomar 5, this globular appears as little more than a smudge of light, and as such is best seen with large aperture scopes or via imaging. It has magnitude of +11.8 but is spread out, so its surface brightness is low. Find it 2.3º to the southwest of M5. The cluster is being disrupted by the gravitation of the Milky Way and there is evidence of streams of stars leaving it. For a while it was thought to be a dwarf galaxy. SEEN ITC
HA
rT A
nd
PH
OTO
: Pe
Te L
AW
ren
Ce
There’s much more to see in the skies around Libra than the ringed wonder of Saturn
Tick the box when you’ve seen each one ✓
Deep-sky tour
-20
ZubENESchaMalI Continue south from Palomar 5 and you’ll reach the constellation of Libra and our next
target – mag. +2.6 Zubeneschamali (Beta (β) Librae). This star is distinct because of reports that it appears to have a green tint. If true, this makes it the only greenish star in the sky visible to the naked eye. A star with peak output in the green part of the spectrum also emits blue and red light. Consequently, our eyes fail to see just green. So does Zubeneschamali actually look green? The only way to tell is to take a look yourself. SEEN IT
NGc 5897 One of the few deep-sky objects in the heart of Libra is globular cluster nGC 5897 – look
for it 1.5º southeast of mag. +4.5 Iota (ι) Librae. nGC 5897 is a broad, diffuse globular that can only be partially resolved, but at mag. +8.6 is considerably easier to identify than Palomar 5. The core looks quite uniform in brightness with no obvious central condensation. Brighter core stars can be made out individually, but the many fainter members merge together like a nebulous haze. There is a notable triple pattern of mag. +11.5 to mag. +13.5 stars located north-northwest of the cluster’s centre. SEEN IT
MErrIll 2-1 There’s another challenging object located 3º to the southeast of nGC 5897, a mag. +11.6
planetary nebula known as Merrill 2-1. This is a tricky spot: the nebula is relatively faint, quite small and located extremely close to a mag. +11.2 star. There’s a mag. +9.9 star designated SAO 183407 50 arcseconds to the west that serves as a good pointer to the area. Once you’ve found the nebula and its close mag. +11.2 star, don’t be afraid to pile on the magnification. At 150x magnification the nebula will start to look like a slightly blurred star. A 6- to 8-inch scope at 200x magnification is needed to show it convincingly. SEEN IT
18 lIbraE Our final object is double star 18 Librae. The primary star is a mag. +5.9 orange
giant that lies 316 lightyears from the Sun. It is fairly easy to locate, being the third point in a squat isosceles triangle that also includes Zubeneschamali (our third stop) and mag. +2.8 Zubenelgenubi (Alpha (α) Librae); the slightly brighter mag. +5.8 Xi1 (ξ1) and mag. +5.5 Xi2 (ξ2) Librae also point toward it. A small scope will reveal that the orange giant has a yellow, mag. +9.9 companion 19.7 arcseconds away. Also look out for a third, mag. +11.5 star 162 arcseconds to the northeast of the primary. SEEN IT
If you have a large scope, look for the ‘strings’ of stars
streaming from M5’s core
2
3
4
5
6
1
0º�
-10º�
-20º�
-20º�
-10º�
0º�
16h
16h 15h
15h
Ecliptic
Celestial Equator
Zubeneschamali
Zubenelgenubi
LIBRA
SCORPIUS
SERPENSCAPUT
VIRGO
Saturn
μ
β
γ
ι
ν
σ
ν β
δ
μ
δ
μ
ξ1ξ2
18
α1
α2
M5
Palomar 5
NGC 5846
NGC 5813
NGC 5634
NGC 5897
IC 4592
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N
E
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16h
16h 15h
15h
Ecliptic
Celestial Equator
Zubeneschamali
Zubenelgenubi
LIBRA
SCORPIUS
SERPENSCAPUT
VIRGO
Saturn
μ
β
γ
ι
ν
σ
ν β
δ
μ
δ
μ
ξ1ξ2
18
α1
α2
M5
Palomar 5
NGC 5846
NGC 5813
NGC 5634
NGC 5897
IC 4592
Merrill 2-1
N
E
S
W
5º
2.5º
1
5
6
2
4
3
CH
ArT
S A
nd
PIC
Ture
S: P
eTe
LAW
ren
Ce
1 M92 Our tour starts with M92, a fine globular cluster that suffers from its proximity to a
far more illustrious one. Start at the northwest corner of the Keystone asterism in Hercules and imagine a line heading northeast to mag. +3.8 Iota (ι) Herculis. Two thirds of the way along this line, M92 shines at mag. +6.4; it has an apparent diameter about one fifth that of the Moon. When you find it, you’ll be looking at the light of a third of a million stars. SEEN IT
2 M13 M92’s more renowned neighbour is M13, which is called the ‘Great Cluster’ for good
reason. Situated a third of the way down the western side of the Keystone asterism, it is visible to the naked eye in a reasonably dark sky. even with small binoculars, this mag. +5.8 globular can be seen in urban skies, although not nearly as splendidly as it appears in darker conditions. In 10x50s, it brightens towards the centre. M13 contains over a million stars. SEEN IT
3 Nu coroNaE borEalIS Line-of-sight double star nu (ν) Coronae Borealis is an easy split in
small binoculars, its distinct deep yellow components appearing a wide 6 arcminutes apart. The pair are remarkably similar, both being advanced giants with masses about 2.5 times that of the Sun. The more northerly star, ν1, sits at 555 lightyears, just 10 lightyears farther away than ν2. It is also a fraction brighter, shining at mag. +5.2, 0.2 magnitudes brighter than ν2 – a result of being about 750 million years more advanced in its evolution and therefore larger and more luminous. SEEN IT
4 Tau coroNaE borEalIS GrouP
Move 4° to the northwest of nu Coranae Borealis and you’ll come to mag. +4.7
Tau (τ) Coronae Borealis, the brightest in a very pretty straight chain (2.5° long) of five stars running east to west. All but the central star shine brighter than mag. +6.0. notice that the
Explore the forgotten cousin of a famous globular, a pair of giants and a starry chain
Tick the box when you’ve seen each one ✓
Binocular tour
mag. +5.6 stars at each end of the chain are a
deeper yellow than the others, while the star next to the eastern end is almost white by comparison. You should find that the mag. +7.4 central star easily resolves into a triple star under dark skies or with larger binoculars. SEEN IT
5 DElTa boöTIS Our penultimate stop is another double star, mag. +3.5 delta (δ) Boötis. The
primary is a deep yellow giant star nearly 60 times more luminous than the Sun. Its yellow-white, mag. +7.8 companion appears to be 105 arcseconds away. delta Boötis is 117 lightyears away, and its components are moving through space together. This confirms that they are a binary star system: they have a separation of at least 0.6 lightyears and an orbital period of at least 120,000 years. SEEN IT
6 rV boöTIS The last stop on this month’s tour is rV Boötis (also designated HIP 71644),
which you can fnd 2.6° northeast of mag. +3.6 rho (ρ) Boötis. rV is nearly midway between two mag. +6.3 stars, the brightest stars in the feld of view of 15x70 binoculars. It is a semi-regular variable with a period between 137 and 144 days, which changes in brightness from mag. +7.2 to mag. +9.8 – although recently it has only been falling to mag. +8.8, so it remains well within reach of binoculars. rV Boötis is a red star, in the latter stage of evolution, on the giant branch of the Hertzsprung-russell diagram. SEEN IT
DRACO
Gemma
Seginus
Nekkar
ArcturusIzar
Muphrid
Kornephoros
Rastaban
HERCULESSERPENSCAPUT
BOÖTES
CORONABOREALIS
Keystone
Kite
M13
M92
β
α
γ
δ
α
γ
δ
β
ε
ρ
ση
ε
γ
β
δ
β γ
ε
ζ
η
π
θ
ι
τ
σ
β
ν
ν1
ν2
τ
RV
NE S
W
5º
1
2
3
4
5
6
With Stephen Tonkin
skyatnightmagazine.com 2014
15 x70
10 x50
10 x50
10 x50
10 x50
15 x70
CH
ArT
S A
nd
PIC
Ture
S: P
eTe
LAW
ren
Ce
1 M92 Our tour starts with M92, a fine globular cluster that suffers from its proximity to a
far more illustrious one. Start at the northwest corner of the Keystone asterism in Hercules and imagine a line heading northeast to mag. +3.8 Iota (ι) Herculis. Two thirds of the way along this line, M92 shines at mag. +6.4; it has an apparent diameter about one fifth that of the Moon. When you find it, you’ll be looking at the light of a third of a million stars. SEEN IT
2 M13 M92’s more renowned neighbour is M13, which is called the ‘Great Cluster’ for good
reason. Situated a third of the way down the western side of the Keystone asterism, it is visible to the naked eye in a reasonably dark sky. even with small binoculars, this mag. +5.8 globular can be seen in urban skies, although not nearly as splendidly as it appears in darker conditions. In 10x50s, it brightens towards the centre. M13 contains over a million stars. SEEN IT
3 Nu coroNaE borEalIS Line-of-sight double star nu (ν) Coronae Borealis is an easy split in
small binoculars, its distinct deep yellow components appearing a wide 6 arcminutes apart. The pair are remarkably similar, both being advanced giants with masses about 2.5 times that of the Sun. The more northerly star, ν1, sits at 555 lightyears, just 10 lightyears farther away than ν2. It is also a fraction brighter, shining at mag. +5.2, 0.2 magnitudes brighter than ν2 – a result of being about 750 million years more advanced in its evolution and therefore larger and more luminous. SEEN IT
4 Tau coroNaE borEalIS GrouP
Move 4° to the northwest of nu Coranae Borealis and you’ll come to mag. +4.7
Tau (τ) Coronae Borealis, the brightest in a very pretty straight chain (2.5° long) of five stars running east to west. All but the central star shine brighter than mag. +6.0. notice that the
Explore the forgotten cousin of a famous globular, a pair of giants and a starry chain
Tick the box when you’ve seen each one ✓
Binocular tour
mag. +5.6 stars at each end of the chain are a
deeper yellow than the others, while the star next to the eastern end is almost white by comparison. You should find that the mag. +7.4 central star easily resolves into a triple star under dark skies or with larger binoculars. SEEN IT
5 DElTa boöTIS Our penultimate stop is another double star, mag. +3.5 delta (δ) Boötis. The
primary is a deep yellow giant star nearly 60 times more luminous than the Sun. Its yellow-white, mag. +7.8 companion appears to be 105 arcseconds away. delta Boötis is 117 lightyears away, and its components are moving through space together. This confirms that they are a binary star system: they have a separation of at least 0.6 lightyears and an orbital period of at least 120,000 years. SEEN IT
6 rV boöTIS The last stop on this month’s tour is rV Boötis (also designated HIP 71644),
which you can fnd 2.6° northeast of mag. +3.6 rho (ρ) Boötis. rV is nearly midway between two mag. +6.3 stars, the brightest stars in the feld of view of 15x70 binoculars. It is a semi-regular variable with a period between 137 and 144 days, which changes in brightness from mag. +7.2 to mag. +9.8 – although recently it has only been falling to mag. +8.8, so it remains well within reach of binoculars. rV Boötis is a red star, in the latter stage of evolution, on the giant branch of the Hertzsprung-russell diagram. SEEN IT
DRACO
Gemma
Seginus
Nekkar
ArcturusIzar
Muphrid
Kornephoros
Rastaban
HERCULESSERPENSCAPUT
BOÖTES
CORONABOREALIS
Keystone
Kite
M13
M92
β
α
γ
δ
α
γ
δ
β
ε
ρ
ση
ε
γ
β
δ
β γ
ε
ζ
η
π
θ
ι
τ
σ
β
ν
ν1
ν2
τ
RV
NE S
W
5º
1
2
3
4
5
6
With Stephen Tonkin
skyatnightmagazine.com 2014
15 x70
10 x50
10 x50
10 x50
10 x50
15 x70
skyatnightmagazine.com 2014
The sky guide APRIL 63
being about 5km deep. Under
good seeing conditions and the
right illumination these cliffs
can be most impressive. The
crater’s foor is largely fat, but
shows a variety of different
tones and textures. To give
you a sense of scale, Humboldt
covers an area of 35,000
square km, which is about 1.5
times the size of Wales.
There is a central mountain
complex and a curious curve
of smaller mountains and hills
arcing off to the northeast. A
smaller, 15km-diameter crater
known as Humboldt N can be
seen to the west, in the
foreground, of this curving
range. This crater and the
mountain range provide the
most obvious visual features
within Humboldt’s rim.
Look carefully and it may be
possible to make out that the
foor of the crater isn’t evenly
toned. There are pyroclastic
patches – dark deposits left
over from volcanic activity
– visible in certain parts of
the foor, most notably in the
southwest round to the west,
and in the northeast.
Moonwatch
CrATer HUmboLdT is
located in the zone of libration
close to the eastern limb of the
moon. The easiest way to fnd
it is to frst identify the more
favourably positioned, 182km-
wide crater Petavius.
Petavius lies 500km to the
west of Humboldt, a distance
that looks much smaller due
to foreshortening at the
moon’s edge. even knowing
this fact, Humboldt can still
be a tricky feature to get to
grips with. in order to see it
convincingly the moon’s
phase has to be just right, as
does the libration. As the
crater is so close to the edge of
the moon, our view of it from
earth foreshortens it into an
ellipse. it can be challenging
to pull the crater out from the
surrounding landscape, but
vigilance reaps rewards.
The crater’s rim is well
defned and lined by some
rather steep cliffs, Humboldt
a number of easily identifable features sit within humboldt’s rim – these include a central peak complex, a mountain range and smaller craters
seen from above by orbiting
spacecraft, Humboldt displays
a delicate pattern of radial
fractures that resembles a
spider’s web. These cracks are
very diffcult to see visually
from earth, but present a
good challenge if you’re into
high-resolution imaging.
Foreshortened regions of
the moon can be very diffcult
to decode. between Petavius
and Humboldt lies 82km-wide
crater Legendre; many of the
smaller craters between it and
Humboldt are catalogued as
being part of the Legendre
family. one notable exception
is the tormented 128km-wide
crater Philips, which sidles up
to the west rim of Humboldt.
if the conditions are really
good, see if you can fnd the
104km-wide crater barnard,
which sits against the southeast
rampart of Humboldt even
nearer to the moon’s edge.
over the coming months
Humboldt’s position will get
less favourable at the same
lunar phase, so make the most
of the conditions during April
to see this amazing crater.
STATISTICSTyPE: CraterSIZE: 213km wide aGE: 3.2 to 3.8 billion years oldlocaTIoN: Latitude 27.2°S, longitude 80.0°E bEST TIME To obSErVE: Two days after new Moon or one day after full Moon (1 and 2 April from 20:00 BST; 30 April and 1 May from 21:00 BST) MINIMuM EquIPMENT: 10x binoculars
Humboldt
“To give you a sense of scale, Humboldt covers an area of 35,000 square km, which is about 1.5 times the size of Wales”
N
E
huMbolDT
huMbolDT N
skyatnightmagazine.com 2014
The sky guide APRIL 63
being about 5km deep. Under
good seeing conditions and the
right illumination these cliffs
can be most impressive. The
crater’s foor is largely fat, but
shows a variety of different
tones and textures. To give
you a sense of scale, Humboldt
covers an area of 35,000
square km, which is about 1.5
times the size of Wales.
There is a central mountain
complex and a curious curve
of smaller mountains and hills
arcing off to the northeast. A
smaller, 15km-diameter crater
known as Humboldt N can be
seen to the west, in the
foreground, of this curving
range. This crater and the
mountain range provide the
most obvious visual features
within Humboldt’s rim.
Look carefully and it may be
possible to make out that the
foor of the crater isn’t evenly
toned. There are pyroclastic
patches – dark deposits left
over from volcanic activity
– visible in certain parts of
the foor, most notably in the
southwest round to the west,
and in the northeast.
Moonwatch
CrATer HUmboLdT is
located in the zone of libration
close to the eastern limb of the
moon. The easiest way to fnd
it is to frst identify the more
favourably positioned, 182km-
wide crater Petavius.
Petavius lies 500km to the
west of Humboldt, a distance
that looks much smaller due
to foreshortening at the
moon’s edge. even knowing
this fact, Humboldt can still
be a tricky feature to get to
grips with. in order to see it
convincingly the moon’s
phase has to be just right, as
does the libration. As the
crater is so close to the edge of
the moon, our view of it from
earth foreshortens it into an
ellipse. it can be challenging
to pull the crater out from the
surrounding landscape, but
vigilance reaps rewards.
The crater’s rim is well
defned and lined by some
rather steep cliffs, Humboldt
a number of easily identifable features sit within humboldt’s rim – these include a central peak complex, a mountain range and smaller craters
seen from above by orbiting
spacecraft, Humboldt displays
a delicate pattern of radial
fractures that resembles a
spider’s web. These cracks are
very diffcult to see visually
from earth, but present a
good challenge if you’re into
high-resolution imaging.
Foreshortened regions of
the moon can be very diffcult
to decode. between Petavius
and Humboldt lies 82km-wide
crater Legendre; many of the
smaller craters between it and
Humboldt are catalogued as
being part of the Legendre
family. one notable exception
is the tormented 128km-wide
crater Philips, which sidles up
to the west rim of Humboldt.
if the conditions are really
good, see if you can fnd the
104km-wide crater barnard,
which sits against the southeast
rampart of Humboldt even
nearer to the moon’s edge.
over the coming months
Humboldt’s position will get
less favourable at the same
lunar phase, so make the most
of the conditions during April
to see this amazing crater.
STATISTICSTyPE: CraterSIZE: 213km wide aGE: 3.2 to 3.8 billion years oldlocaTIoN: Latitude 27.2°S, longitude 80.0°E bEST TIME To obSErVE: Two days after new Moon or one day after full Moon (1 and 2 April from 20:00 BST; 30 April and 1 May from 21:00 BST) MINIMuM EquIPMENT: 10x binoculars
Humboldt
“To give you a sense of scale, Humboldt covers an area of 35,000 square km, which is about 1.5 times the size of Wales”
N
E
huMbolDT
huMbolDT N
64
mArs is A bit of a tease as far as practical
astronomy is concerned. After lurking in
tricky parts of the sky and looking rather
diminutive for many months, it bursts
back onto the scene for a short period, before
fading into the background once again.
This month it reaches opposition, so this
is the best time to both observe and image
it. Here, we’ll look at how to do the latter
with a mono high frame rate camera and
a set of rGb imaging flters.
mars is a captivating astrophotography
target because it is the closest world we can
see that has reasonable similarity to earth,
in that it shows both surface features and
weather. From earth we can see brighter
deserts, darker rock and gleaming polar
caps. These are ‘albedo features’; they are
visible because they have notably different
refectivity (albedo) to adjacent areas.
Features such as craters, mountains and
valleys are much harder to image from
earth because of their small apparent size
at the planet’s vast distance. Known as
AstrophotographyImaging Mars at opposition
ALL
PIC
Tu
reS: PeTe L
AW
ren
Ce
need to try and complete the entire
capture sequence in less than fve minutes.
For a colour camera this isn’t too hard,
but when trying to capture images using
several flters it is more of a concern.
Advanced processing techniques such as
derotation can be used to address motion
blur, but there’s an easier solution that
hinges around the lack of signifcant detail
visible in the green flter – simply abstain
from taking a green-fltered image in the
frst place. it may sound crazy, but the green
image can be artifcially synthesised from
the red and blue results. The fnal colour
image will look almost identical to what
you would have achieved using a full set of
rGb images, but you’ll reduce the time it
needed for your capture sequence by a third.
Generating a synthetic green image also
streamlines the capture process, allowing
you to generate a smooth sequence of
mars images for animation purposes. For
example, a run of rbrbrb captures would
allow you to create an r(G)b result using
the frst rb pair – the parentheses indicate
that the green is synthetic – then
a second b(G)r result using the frst br
pair. A third r(G)b result would be created
using the second rb pair, and so on. With
a fairly short time gap between r(G)b
results, these can be animated together
to produce a smooth fowing rotation
sequence of this fascinating world.
‘relief’ features, these would normally be
revealed because height variation causes
them to cast shadows, just like elevated
structures close to the terminator do
on the moon. From earth, the martian
shadows are tiny and hard to pick out,
so the main features of interest for mars
imagers are albedo based rather than relief.
Using a mono high frame rate camera
and rGb flters, mars’s refectivity
becomes quite interesting – the reason for
this is that the ‘information’ that passes
through a green flter gives very little
extra image detail than can be obtained
with red and blue flters alone. This
surprising fact can be used to help
overcome one of the main issues when
rGb imaging a relatively fast rotating
planet such as mars: if you take too long
to collect an image set, the fnal rGb may
show motion blur. For this reason, you
Send your image to: hotshots@skyatnightmagazine.com
skyatnightmagazine.com 2014
ReCommended equIPmenT8-inch or larger scope, Barlow lens, monochrome high frame rate camera, RGB imaging flters mounted in a flter wheel
Key TeChnIqueSyNThETIc colourSAlthough colour cameras are catching up, mono cameras still have the edge when it comes to planetary imaging. For a full-colour result from a mono camera you need red, green and blue imaging filters; this significantly reduces colour-related problems such as chromatic aberration and atmospheric dispersion. Unfortunately, filtered sequences take longer to complete and overly long capture may result in motion blur – but using a synthetic green capture can help. Find out how in the step-by-step.
your fnal image will reveal the red
Planet’s large albedo surface features
64
mArs is A bit of a tease as far as practical
astronomy is concerned. After lurking in
tricky parts of the sky and looking rather
diminutive for many months, it bursts
back onto the scene for a short period, before
fading into the background once again.
This month it reaches opposition, so this
is the best time to both observe and image
it. Here, we’ll look at how to do the latter
with a mono high frame rate camera and
a set of rGb imaging flters.
mars is a captivating astrophotography
target because it is the closest world we can
see that has reasonable similarity to earth,
in that it shows both surface features and
weather. From earth we can see brighter
deserts, darker rock and gleaming polar
caps. These are ‘albedo features’; they are
visible because they have notably different
refectivity (albedo) to adjacent areas.
Features such as craters, mountains and
valleys are much harder to image from
earth because of their small apparent size
at the planet’s vast distance. Known as
AstrophotographyImaging Mars at opposition
ALL
PIC
Tu
reS:
PeTe L
AW
ren
Ce
need to try and complete the entire
capture sequence in less than fve minutes.
For a colour camera this isn’t too hard,
but when trying to capture images using
several flters it is more of a concern.
Advanced processing techniques such as
derotation can be used to address motion
blur, but there’s an easier solution that
hinges around the lack of signifcant detail
visible in the green flter – simply abstain
from taking a green-fltered image in the
frst place. it may sound crazy, but the green
image can be artifcially synthesised from
the red and blue results. The fnal colour
image will look almost identical to what
you would have achieved using a full set of
rGb images, but you’ll reduce the time it
needed for your capture sequence by a third.
Generating a synthetic green image also
streamlines the capture process, allowing
you to generate a smooth sequence of
mars images for animation purposes. For
example, a run of rbrbrb captures would
allow you to create an r(G)b result using
the frst rb pair – the parentheses indicate
that the green is synthetic – then
a second b(G)r result using the frst br
pair. A third r(G)b result would be created
using the second rb pair, and so on. With
a fairly short time gap between r(G)b
results, these can be animated together
to produce a smooth fowing rotation
sequence of this fascinating world.
‘relief’ features, these would normally be
revealed because height variation causes
them to cast shadows, just like elevated
structures close to the terminator do
on the moon. From earth, the martian
shadows are tiny and hard to pick out,
so the main features of interest for mars
imagers are albedo based rather than relief.
Using a mono high frame rate camera
and rGb flters, mars’s refectivity
becomes quite interesting – the reason for
this is that the ‘information’ that passes
through a green flter gives very little
extra image detail than can be obtained
with red and blue flters alone. This
surprising fact can be used to help
overcome one of the main issues when
rGb imaging a relatively fast rotating
planet such as mars: if you take too long
to collect an image set, the fnal rGb may
show motion blur. For this reason, you
Send your image to: hotshots@skyatnightmagazine.com
skyatnightmagazine.com 2014
ReCommended equIPmenT8-inch or larger scope, Barlow lens, monochrome high frame rate camera, RGB imaging flters mounted in a flter wheel
Key TeChnIqueSyNThETIc colourSAlthough colour cameras are catching up, mono cameras still have the edge when it comes to planetary imaging. For a full-colour result from a mono camera you need red, green and blue imaging filters; this significantly reduces colour-related problems such as chromatic aberration and atmospheric dispersion. Unfortunately, filtered sequences take longer to complete and overly long capture may result in motion blur – but using a synthetic green capture can help. Find out how in the step-by-step.
your fnal image will reveal the red
Planet’s large albedo surface features
skyatnightmagazine.com 2014
The sky guide APRIL 65
STeP-By-STeP GuIde
sTep 2 With Mars on chip, select the red flter and focus as quickly and accurately as possible. aim to collect 2,000-3,000 frames, although try to avoid imaging for more than 90 seconds per flter. adjust the camera gain and frame rate if necessary to maximise the saturation level for each flter to around 80-90 per cent.
sTep 3 Switch to your blue flter, quickly re-focus and capture the blue image. repeat the rb sequence as many times as required. When done, load each capture into a stacking program, such as the freeware regiStax, and process each through to wavelet sharpening. apply a subtle amount of wavelet sharpening to the end result as required.
sTep 6 Switch to the layers list and duplicate the base r(G)b layer to make your fnal tweaks. If the colour looks off or subdued, try using the program’s auto-colour function; if the colours look too strong after this, try fading the auto-colour back a bit. adjust the fnal levels, contrast and brightness to taste. apply sharpening sparingly.
sTep 1 Mars has an apparent diameter of 15 arcseconds at opposition, so you’ll need a decent image scale to show much detail. as a guide, aim for a focal ratio of between f/15 and f/45, adjusted by using optical amplifers such as a barlow lens. only use a high image scale if the seeing is good.
sTep 4 load an rb pair into a layer-based editor as separate layers. adjust the upper image so that it is aligned with the lower one. crop to remove any whites edges this creates. Duplicate the r and b layers and move to the top of layer stack. Make top layer 50 per cent transparent and merge with the one below – this creates the synthetic green.
sTep 5 create a blank rGb image with the same dimensions as the image you were working on in step 4. copy the r image layer to the red channel in the blank image. repeat for the (G) and b layers, pasting them into their respective green and blue channels. The result should be a full colour r(G)b image showing the distinctive colours of Mars.
skyatnightmagazine.com 2014
The sky guide APRIL 65
STeP-By-STeP GuIde
sTep 2 With Mars on chip, select the red flter and focus as quickly and accurately as possible. aim to collect 2,000-3,000 frames, although try to avoid imaging for more than 90 seconds per flter. adjust the camera gain and frame rate if necessary to maximise the saturation level for each flter to around 80-90 per cent.
sTep 3 Switch to your blue flter, quickly re-focus and capture the blue image. repeat the rb sequence as many times as required. When done, load each capture into a stacking program, such as the freeware regiStax, and process each through to wavelet sharpening. apply a subtle amount of wavelet sharpening to the end result as required.
sTep 6 Switch to the layers list and duplicate the base r(G)b layer to make your fnal tweaks. If the colour looks off or subdued, try using the program’s auto-colour function; if the colours look too strong after this, try fading the auto-colour back a bit. adjust the fnal levels, contrast and brightness to taste. apply sharpening sparingly.
sTep 1 Mars has an apparent diameter of 15 arcseconds at opposition, so you’ll need a decent image scale to show much detail. as a guide, aim for a focal ratio of between f/15 and f/45, adjusted by using optical amplifers such as a barlow lens. only use a high image scale if the seeing is good.
sTep 4 load an rb pair into a layer-based editor as separate layers. adjust the upper image so that it is aligned with the lower one. crop to remove any whites edges this creates. Duplicate the r and b layers and move to the top of layer stack. Make top layer 50 per cent transparent and merge with the one below – this creates the synthetic green.
sTep 5 create a blank rGb image with the same dimensions as the image you were working on in step 4. copy the r image layer to the red channel in the blank image. repeat for the (G) and b layers, pasting them into their respective green and blue channels. The result should be a full colour r(G)b image showing the distinctive colours of Mars.
As two more sites in northern England and Scotland earn Dark Sky status, Paul F Cockburn hears how they achieved the award
Light pollution has been a
growing problem for the past
century, which has seen our
view of the night sky obscured
by the glow of artifcial lighting.
Since 2003, the annual International
Dark Sky Week – this year’s is 20-26
April – has become an umbrella for
events that remind people not just of the
wonder and beauty above their heads,
but also how light pollution can disrupt
the natural environment, waste energy
and affect human health. One ongoing
response has been the identifcation,
recognition and protection of areas
around the world that are still largely
free of signifcant light pollution.
It started in 2006, when the US-based
International Dark Sky Association
established a programme to classify Dark
Sky Parks, Reserves and Communities.
Galloway Forest Park in Scotland was
the frst area in the UK to ft the bill,
attaining Dark Sky status in 2009; the
Island of Sark and Exmoor National
Park followed suit in 2011, then Brecon
Beacons National Park in early 2013.
December 2013 saw two more, bringing
the UK’s total to six: Northumberland
National Park joined with neighbouring
Kielder Water and Forest Park to create
a single Dark Sky Park, and the Island
of Coll in Scotland became a Dark
Sky Community. We spoke to some
of the people who made these latest
designations possible. KIL
ED
ER W
ATER A
ND
FO
REST P
ARK
Dark skiesRECOGNISEDAs two more sites in northern England and Scotland earn Dark Sky status, Paul F Cockburn hears how they achieved the award
Light pollution has been a
growing problem for the past
century, which has seen our
view of the night sky obscured
by the glow of artifcial lighting.
Since 2003, the annual International
Dark Sky Week – this year’s is 20-26
April – has become an umbrella for
events that remind people not just of the
wonder and beauty above their heads,
but also how light pollution can disrupt
the natural environment, waste energy
and affect human health. One ongoing
response has been the identifcation,
recognition and protection of areas
around the world that are still largely
free of signifcant light pollution.
It started in 2006, when the US-based
International Dark Sky Association
established a programme to classify Dark
Sky Parks, Reserves and Communities.
Galloway Forest Park in Scotland was
the frst area in the UK to ft the bill,
attaining Dark Sky status in 2009; the
Island of Sark and Exmoor National
Park followed suit in 2011, then Brecon
Beacons National Park in early 2013.
December 2013 saw two more, bringing
the UK’s total to six: Northumberland
National Park joined with neighbouring
Kielder Water and Forest Park to create
a single Dark Sky Park, and the Island
of Coll in Scotland became a Dark
Sky Community. We spoke to some
of the people who made these latest
designations possible. KIL
ED
ER W
ATER A
ND
FO
REST P
ARK
Dark skiesRECOGNISED
ABOUT THE WRITER
Paul F Cockburn is a freelance journalist who has been writing about science and technology – past and future – since 1996.
The success of Kielder Observatory made applying for
Dark Sky status a natural step
ABOUT THE WRITER
Paul F Cockburn is a freelance journalist who has been writing about science and technology – past and future – since 1996.
The success of Kielder Observatory made applying for
Dark Sky status a natural step
68
skyatnightmagazine.com 2014
“Tranquility has been
recognised as one of the
main special qualities
of Northumberland National Park,”
says chief executive Tony Gates. “That
sense of the unspoilt, which is
something that we know residents
and visitors really value, we felt also
extended to the skies.”
So, when applying for Dark Sky Park
status, Gates believes they started from
a very good base. “We needed to change
very little really,” he says. “The survey
of our existing skies, which was part of
the application, showed we already had
a very high level of darkness, which led
to us being designated gold status.
“Our intention was always to ensure
we protected the levels of dark skies
and, where there were opportunities
to enhance them, that we did,” Gates
adds. “What we’ve found through this
process is that people have really come
on board: it’s really tapped into just
how much they value the dark skies.
We had people voluntarily adjusting
the angles of outdoor spotlights,
adjusting the fttings.”
Adding weight to Northumberland
National Park’s application was the
fact that it was jointly made with
neighbouring Kielder Water and Forest
Park. “In their case the application was
largely driven by the popularity of the
Kiedler Observatory and the sudden
realisation that the dark skies were really
widely valued,” says Gates. “It just so
happened that the two parks were working
on this idea at the same time, so we
decided to put our lot together.”
Northumberland National Park
The initial inspiration behind attaining Dark Sky status was simple, according to chair of the
Kielder Water and Forest Park Development Trust, Heidi Mottram – it was the success of the Kielder Observatory, opened in 2008.
The trust has long been looking for new ways to promote economic
development in the area, as a way of helping ensure it remains a vibrant, living community.
“The idea really came from the Kielder Observatory and just grew,” says Mottram. “The local community became quite excited about it. At one level I think we already knew that the sky was stunning, that we had a fabulous asset, that it was pretty dark and that the changes required by the lighting audits were generally
Kielder Water and Forest Park
minor – a large part of the park is uninhabited anyway.”
She adds that the engagement of local communities has been great. “At one primary school, the children really got into it and designed covers for the school’s unshielded lights,” she says. “They really embraced the whole thing. One of the villages has had its lights replaced with LED units – there have been some changes, but nothing I would describe as massive.”
TONY GATES Chief executive
ALA
MY,
KIL
EDER
WA
TER
AN
D F
ORE
ST P
ARK
, W
ILL
GA
TER,
ALE
x SP
EED
Quite early on, the trust linked up with the application being made by neighbouring Northumberland National Park. “In many respects, that way of working is embedded here,” Mottram says.
“People in these communities recognise that because they’re so small on their own, it’s often diffcult to do anything. The two parks are side by side; it was obvious we should work together.”
HEIDI MOTTRAM Chairperson
Comet Hale-Bopp shines bright in the darkness of
Northumberland National Park
A sycamore stands alone against the starry
skyscape over Kielder
68
skyatnightmagazine.com 2014
“Tranquility has been
recognised as one of the
main special qualities
of Northumberland National Park,”
says chief executive Tony Gates. “That
sense of the unspoilt, which is
something that we know residents
and visitors really value, we felt also
extended to the skies.”
So, when applying for Dark Sky Park
status, Gates believes they started from
a very good base. “We needed to change
very little really,” he says. “The survey
of our existing skies, which was part of
the application, showed we already had
a very high level of darkness, which led
to us being designated gold status.
“Our intention was always to ensure
we protected the levels of dark skies
and, where there were opportunities
to enhance them, that we did,” Gates
adds. “What we’ve found through this
process is that people have really come
on board: it’s really tapped into just
how much they value the dark skies.
We had people voluntarily adjusting
the angles of outdoor spotlights,
adjusting the fttings.”
Adding weight to Northumberland
National Park’s application was the
fact that it was jointly made with
neighbouring Kielder Water and Forest
Park. “In their case the application was
largely driven by the popularity of the
Kiedler Observatory and the sudden
realisation that the dark skies were really
widely valued,” says Gates. “It just so
happened that the two parks were working
on this idea at the same time, so we
decided to put our lot together.”
Northumberland National Park
The initial inspiration behind attaining Dark Sky status was simple, according to chair of the
Kielder Water and Forest Park Development Trust, Heidi Mottram – it was the success of the Kielder Observatory, opened in 2008.
The trust has long been looking for new ways to promote economic
development in the area, as a way of helping ensure it remains a vibrant, living community.
“The idea really came from the Kielder Observatory and just grew,” says Mottram. “The local community became quite excited about it. At one level I think we already knew that the sky was stunning, that we had a fabulous asset, that it was pretty dark and that the changes required by the lighting audits were generally
Kielder Water and Forest Park
minor – a large part of the park is uninhabited anyway.”
She adds that the engagement of local communities has been great. “At one primary school, the children really got into it and designed covers for the school’s unshielded lights,” she says. “They really embraced the whole thing. One of the villages has had its lights replaced with LED units – there have been some changes, but nothing I would describe as massive.”
TONY GATES Chief executive
ALA
MY,
KIL
EDER
WA
TER
AN
D F
ORE
ST P
ARK
, W
ILL
GA
TER,
ALE
x SP
EED
Quite early on, the trust linked up with the application being made by neighbouring Northumberland National Park. “In many respects, that way of working is embedded here,” Mottram says.
“People in these communities recognise that because they’re so small on their own, it’s often diffcult to do anything. The two parks are side by side; it was obvious we should work together.”
HEIDI MOTTRAM Chairperson
Comet Hale-Bopp shines bright in the darkness of
Northumberland National Park
A sycamore stands alone against the starry
skyscape over Kielder
dark sky sites april 69
skyatnightmagazine.com 2014
“We stared out with
just two designations
– Reserve and Park,”
says Bob Parks, executive director of the
International Dark Skies Association.
“Then we added Community. The system
evolves over time to take account of
the types of areas where people are
interested; we’re fnding, as we continue
to expand the programme, that one
size defnitely doesn’t ft all, so we’re
trying to make adjustments.”
So what are the current technical
distinctions between the different kinds
of Dark Sky places? “Starting at the
larger end of the spectrum, a ‘Reserve’
is not required to be protected by a
government entity,” Parks says. “You can
develop a Reserve around any property
that the community and residents
are interested in protecting. A ‘Park’
specifcally has to have public protection,
which also ensures it’s not private
land. On the municipal end of the
spectrum, ‘Community’ is for
townships and cities, places that
are incorporated entities.”
The association is also introducing
a category called Development of
Distinction. “That’s one step down the
chain for residential developments that
may not be a town or city, but have an
interest in protecting the development.
We’re actually looking now at another
designation, or modifying current
ones. For example, two islands are part
of the programme, and in both cases
ESA’s JUICE mission, due to launch in 2022, will study the Galilean moons in greater detail than ever before
BOB PARKS
Executive director
they did not ft in anything except
Community because they were protected
by natural boundaries; they didn’t
really have a buffer zone to make either
a Reserve.
“Some areas that aren’t surrounded
by water have that same issue,” he adds.
“If they are surrounded by public land,
they sometimes can’t really incorporate
that into the equation as a buffer zone
because there isn’t a township or local
authority in the area that’s able to
sign a declaration of intent to abide
by our guidelines.
It’s not all about darkness“We don’t look for quantities of
designation; we’re not looking to have
hundreds of these,” Parks insists.
“Any decision is based on the merits
of the application. What we look for
is extraordinary dedication to the
preservation of that area in the future.
It doesn’t matter whether the area is
as dark as it possibly can be; what
we’re looking for is a community that’s
willing to make the changes and have
the dedication to try to preserve that
for the next generation.
“These applications take a long
time to prepare: they’re not easy,”
he adds. “Some people get into them
and then fnd out pretty quickly that
these are not a quick path to fame
and fortune. Different countries now
want to have their own Dark Sky
Parks, but the level of cooperation
and collaboration required to get
all the different parties to agree to
something is diffcult. It takes a
sustained effort by a community over
a long period of time.”
International Dark Skies Association
Galloway was the frst Dark Sky place in the UK, earning its award in 2009
The UK now boasts six Dark Sky places, the others being Sark,
Exmoor and – shown here – the Brecon Beacons
dark sky sites april 69
skyatnightmagazine.com 2014
“We stared out with
just two designations
– Reserve and Park,”
says Bob Parks, executive director of the
International Dark Skies Association.
“Then we added Community. The system
evolves over time to take account of
the types of areas where people are
interested; we’re fnding, as we continue
to expand the programme, that one
size defnitely doesn’t ft all, so we’re
trying to make adjustments.”
So what are the current technical
distinctions between the different kinds
of Dark Sky places? “Starting at the
larger end of the spectrum, a ‘Reserve’
is not required to be protected by a
government entity,” Parks says. “You can
develop a Reserve around any property
that the community and residents
are interested in protecting. A ‘Park’
specifcally has to have public protection,
which also ensures it’s not private
land. On the municipal end of the
spectrum, ‘Community’ is for
townships and cities, places that
are incorporated entities.”
The association is also introducing
a category called Development of
Distinction. “That’s one step down the
chain for residential developments that
may not be a town or city, but have an
interest in protecting the development.
We’re actually looking now at another
designation, or modifying current
ones. For example, two islands are part
of the programme, and in both cases
ESA’s JUICE mission, due to launch in 2022, will study the Galilean moons in greater detail than ever before
BOB PARKS
Executive director
they did not ft in anything except
Community because they were protected
by natural boundaries; they didn’t
really have a buffer zone to make either
a Reserve.
“Some areas that aren’t surrounded
by water have that same issue,” he adds.
“If they are surrounded by public land,
they sometimes can’t really incorporate
that into the equation as a buffer zone
because there isn’t a township or local
authority in the area that’s able to
sign a declaration of intent to abide
by our guidelines.
It’s not all about darkness“We don’t look for quantities of
designation; we’re not looking to have
hundreds of these,” Parks insists.
“Any decision is based on the merits
of the application. What we look for
is extraordinary dedication to the
preservation of that area in the future.
It doesn’t matter whether the area is
as dark as it possibly can be; what
we’re looking for is a community that’s
willing to make the changes and have
the dedication to try to preserve that
for the next generation.
“These applications take a long
time to prepare: they’re not easy,”
he adds. “Some people get into them
and then fnd out pretty quickly that
these are not a quick path to fame
and fortune. Different countries now
want to have their own Dark Sky
Parks, but the level of cooperation
and collaboration required to get
all the different parties to agree to
something is diffcult. It takes a
sustained effort by a community over
a long period of time.”
International Dark Skies Association
Galloway was the frst Dark Sky place in the UK, earning its award in 2009
The UK now boasts six Dark Sky places, the others being Sark,
Exmoor and – shown here – the Brecon Beacons
skyatnightmagazine.com 2014
1 Brecon Beacons National Park International Dark Sky ReserveNational Park Visitor Centre Libanus, Brecon, Powys, LD3 8ER01874 623366www.beacons-npa.gov.uk/contact-us www.beacons-npa.gov.uk
2 Exmoor National ParkInternational Dark Sky ReserveDulverton National Park Centre7-9 Fore Street, Dulverton, TA22 9EX 01398 323841 NPCDulverton@exmoor-nationalpark.gov.uk www.exmoor-nationalpark.gov.uk
3 Galloway Forest ParkInternational Dark Sky ParkGalloway Astronomy CentreA747, three miles east of Monreith01988 500594 enquiries@gallowayastro.com www.forestry.gov.uk/darkskygalloway
4 Isle of Coll International Dark Sky Communityc/o The Coll Hotel
Arinagour, Isle of Coll, PA78 6SZ01879 230334 info@collhotel.com http://darkskies.visitcoll.co.uk
5 Northumberland National Park and Kielder Water and Forest Park International Dark Sky ParkOnce Brewed Visitor Centre Military Road, Bardon Mill, Hexham, NE47 7AN 01434 344396 tic.oncebrewed@nnpa.org.uk www.northumberlandnationalpark.org.uk
Kielder ObservatoryBlack Fell, Off Shilling Pot, Kielder, NE48 1EJ07805 638469 gary@kielderobservatory.orgwww.kielderobservatory.org
6 Isle of Sark International Dark Sky Communitywww.sark.co.uk Sark Tourist OffceThe Avenue, Sark Island, GY10 1SA01481 832345 offce@sark.co.uk
Visiting the UK’s Dark Sky sites
70 dark sky sites april
“An International Dark
Sky Community is a
town, city, municipality,
or other legally organised community
that shows what the International Dark
Sky Association describes as ‘exceptional
dedication’ to preserving the night sky,”
explains amateur astronomer Olvin Smith,
who lives on the Inner Hebridean island
of Coll – since December 2013 the second
Dark Sky Community in Britain.
“It started around two years ago when
fellow astronomer Tony Oliver saw that Sark
had been awarded the status and thought
that we should get it as well,” Smith says.
“This led to a meeting which ended up
with a core group of four – myself, Tony,
hotel owner Julie Oliphant and guest house
owner Paula Smalley taking it forward. We
got in touch with the association, and had a
couple of phone calls with chief executive Bob
Parks, who talked us through the process.
Having purchased a Unihedron [sky quality]
meter, Smith completed a light survey
around the island. “On several sites I got
readings of 21.9 [magnitudes per square
arcsecond], which make our skies some of
the darkest in Europe,” he says. “Once we
had all the data, and with the help of a dark
skies consultant, Tony put together our
application, which was fnished last May.
“We had to alter some of the lights to
make them point straight down and get
commitment from some people to change
their outside lights to correct type,” Smith
notes. “We also needed to get the council
to endorse our lighting plan.”
It’s been very much a ‘ground up’
affair, Smith insists. “The community
has done all the work without any outside
funding; the money and work came
from the islanders.”
Isle of CollOLvIN SMITH
Amateur astronomer
CO
LL D
ARK
SK
Y G
RO
UP
1
2
3
4
5
6
Coll is Britain’s second Dark Sky Community
skyatnightmagazine.com 2014
1 Brecon Beacons National Park International Dark Sky ReserveNational Park Visitor Centre Libanus, Brecon, Powys, LD3 8ER01874 623366www.beacons-npa.gov.uk/contact-us www.beacons-npa.gov.uk
2 Exmoor National ParkInternational Dark Sky ReserveDulverton National Park Centre7-9 Fore Street, Dulverton, TA22 9EX 01398 323841 NPCDulverton@exmoor-nationalpark.gov.uk www.exmoor-nationalpark.gov.uk
3 Galloway Forest ParkInternational Dark Sky ParkGalloway Astronomy CentreA747, three miles east of Monreith01988 500594 enquiries@gallowayastro.com www.forestry.gov.uk/darkskygalloway
4 Isle of Coll International Dark Sky Communityc/o The Coll Hotel
Arinagour, Isle of Coll, PA78 6SZ01879 230334 info@collhotel.com http://darkskies.visitcoll.co.uk
5 Northumberland National Park and Kielder Water and Forest Park International Dark Sky ParkOnce Brewed Visitor Centre Military Road, Bardon Mill, Hexham, NE47 7AN 01434 344396 tic.oncebrewed@nnpa.org.uk www.northumberlandnationalpark.org.uk
Kielder ObservatoryBlack Fell, Off Shilling Pot, Kielder, NE48 1EJ07805 638469 gary@kielderobservatory.orgwww.kielderobservatory.org
6 Isle of Sark International Dark Sky Communitywww.sark.co.uk Sark Tourist OffceThe Avenue, Sark Island, GY10 1SA01481 832345 offce@sark.co.uk
Visiting the UK’s Dark Sky sites
70 dark sky sites april
“An International Dark
Sky Community is a
town, city, municipality,
or other legally organised community
that shows what the International Dark
Sky Association describes as ‘exceptional
dedication’ to preserving the night sky,”
explains amateur astronomer Olvin Smith,
who lives on the Inner Hebridean island
of Coll – since December 2013 the second
Dark Sky Community in Britain.
“It started around two years ago when
fellow astronomer Tony Oliver saw that Sark
had been awarded the status and thought
that we should get it as well,” Smith says.
“This led to a meeting which ended up
with a core group of four – myself, Tony,
hotel owner Julie Oliphant and guest house
owner Paula Smalley taking it forward. We
got in touch with the association, and had a
couple of phone calls with chief executive Bob
Parks, who talked us through the process.
Having purchased a Unihedron [sky quality]
meter, Smith completed a light survey
around the island. “On several sites I got
readings of 21.9 [magnitudes per square
arcsecond], which make our skies some of
the darkest in Europe,” he says. “Once we
had all the data, and with the help of a dark
skies consultant, Tony put together our
application, which was fnished last May.
“We had to alter some of the lights to
make them point straight down and get
commitment from some people to change
their outside lights to correct type,” Smith
notes. “We also needed to get the council
to endorse our lighting plan.”
It’s been very much a ‘ground up’
affair, Smith insists. “The community
has done all the work without any outside
funding; the money and work came
from the islanders.”
Isle of CollOLvIN SMITH
Amateur astronomer
CO
LL D
ARK
SK
Y G
RO
UP
1
2
3
4
5
6
Coll is Britain’s second Dark Sky Community
SP
EC
IAL
ED
ITIO
N
What are the deadliest animals?
How high are the tallest skyscrapers?
Which inventors were killed by their
own creations?
From the biggest and highest to the
strongest and hottest, the extremes of
life as we know it are revealed by The Big
Book Of Top 10s.
This 116-page special edition by
the makers of BBC Focus Magazine
explores science, technology, space, the
animal world, evolution, history and more
to explain how our planet works.
NEW FROM
The Earth is an amazing place: compare its longest rivers and highest mountains
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Journey to the final frontier, from the brightest stars to the biggest moons
Discover amazing feats of engineering that have left their mark on the planet
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SP
EC
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What are the deadliest animals?
How high are the tallest skyscrapers?
Which inventors were killed by their
own creations?
From the biggest and highest to the
strongest and hottest, the extremes of
life as we know it are revealed by The Big
Book Of Top 10s.
This 116-page special edition by
the makers of BBC Focus Magazine
explores science, technology, space, the
animal world, evolution, history and more
to explain how our planet works.
NEW FROM
The Earth is an amazing place: compare its longest rivers and highest mountains
+Calls to this number from a BT landline will cost no more than 5p per minute. Calls from mobiles and other providers may vary. Lines are open 8am-8pm weekdays & 9am-1pm Saturday.
*Prices including postage are: £9.49 for UK residents, £10.99 for Europe and £11.49 for Rest of World. All orders subject to availability. Please allow up to 21 days for delivery.
Journey to the final frontier, from the brightest stars to the biggest moons
Discover amazing feats of engineering that have left their mark on the planet
ORDER TODAY ATwww.buysubscriptions.com/FOCUS10 0844 844 0388+
Or call our order hotline
Please quote
TOPHAX14
ONLY
£7.99
+P&P*
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Two centuries after Fraunhofer discovered dark lines in the Sun’s spectrum, Will Gater looks at the next generation of spectroscopes
Every day, as Earth’s terminator sweeps
around the globe, the Sun sets in some
part of the world and the blue sky
deepens. On mountaintops and high
desert plateaus, domes open and motors whirr
as various kinds of astronomical machinery
housed in observatories heaves into life.
Like the coral polyps that emerge at night to
feed, the telescopes inside these observatories
are on the hunt for passing quarry. Yet they seek
something far more exotic than even the most
unusual plankton: photons of celestial light.
Photons that may have been travelling for billions
of years across unimaginably vast stretches of
space. Photons that, crucially, can reveal the
secrets of the objects they’ve come from.
As they peer out into space, the huge mirrors
of the world’s professional telescopes catch some
of these precious photons. Sensitive cameras can
record the light if need be, producing pictures
of stars, nebulae and galaxies that enable
astronomers to piece together the story of their
distant subjects. But to delve deeper into what
this light can tell them, astronomers must turn
unlockingThe SecreTS oF
>
thin
ksto
ck
, a
lam
y
Two centuries after Fraunhofer discovered dark lines in the Sun’s spectrum, Will Gater looks at the next generation of spectroscopes
Every day, as Earth’s terminator sweeps
around the globe, the Sun sets in some
part of the world and the blue sky
deepens. On mountaintops and high
desert plateaus, domes open and motors whirr
as various kinds of astronomical machinery
housed in observatories heaves into life.
Like the coral polyps that emerge at night to
feed, the telescopes inside these observatories
are on the hunt for passing quarry. Yet they seek
something far more exotic than even the most
unusual plankton: photons of celestial light.
Photons that may have been travelling for billions
of years across unimaginably vast stretches of
space. Photons that, crucially, can reveal the
secrets of the objects they’ve come from.
As they peer out into space, the huge mirrors
of the world’s professional telescopes catch some
of these precious photons. Sensitive cameras can
record the light if need be, producing pictures
of stars, nebulae and galaxies that enable
astronomers to piece together the story of their
distant subjects. But to delve deeper into what
this light can tell them, astronomers must turn
unlockingThe SecreTS oF
>
74
skyatnightmagazine.com 2014
ala
my x
3, n
.a.s
ha
rp/
no
ao
/n
so
/k
itt
pea
k F
ts/a
Ur
a/n
sF,
ea
ds a
str
iUm
, th
ink
sto
ck
to another, less celebrated, tool of astronomical
discovery – the spectrograph.
The realisation that light could harbour
information about celestial objects came thanks
to the work of the German glass-maker Joseph von
Fraunhofer. In 1814 he dispersed the Sun’s light
into a rainbow of colours – known as a spectrum
– discovering numerous dark absorption lines (see
‘The Science of Spectra’, right) that were later found
to betray the composition of our star. With the
subsequent development of spectroscopes to view –
and spectrographs to record – celestial spectra and
the lines they contained, astronomers had a means
to examine the make-up of stars.
The next generationEver since those early days, spectroscopy and
the spectrograph have been an integral part of
astronomical research, giving astronomers insights
into not just the composition of faraway bodies
but also their temperature, distance and even
movements. Now, two centuries after Fraunhofer’s
studies, astronomers are readying a new generation
of spectrographs to explore the Universe, the likes
of which have never been seen before.
Under the bright lights of the cavernous High Bay
clean room at NASA’s Goddard Space Flight Center
in Maryland, the James Webb Space Telescope is
slowly taking shape. Yellow scissor fences carefully
partition off areas of the immaculate, white-foored
room where instruments and other structures rest
on substantial support stands. High above, on an
enormous gantry, each of the telescope’s 18 primary
mirror segments sit protected within huge polished
metal containers. Gradually, the components
are being meticulously tested and, eventually,
integrated into the telescope’s skeleton, ahead of
its planned launch in 2018.
Sitting in its own corner of the Goddard clean
room, NIRSpec – the Near-Infrared Spectrograph
– is just one of the four instruments that will
fy on James Webb. As with all of the telescope’s
instruments, it will focus on observing the Universe
at infrared wavelengths. To understand why, you
only need to look at the work of James Webb’s
forebear, the Hubble Space Telescope.
Hubble has excelled at studying faraway galaxies
as well as extrasolar planets and how they form
within vast clouds of dust and gas. But to peer
Þ Lines in the Sun’s spectrum show which wavelengths of light have been absorbed by its atmosphere
Joseph von Fraunhofer, left, demonstrates his spectrocope in Munich in 1814
>
74
skyatnightmagazine.com 2014
ala
my x
3, n
.a.s
ha
rp/
no
ao
/n
so
/k
itt
pea
k F
ts/a
Ur
a/n
sF,
ea
ds a
str
iUm
, th
ink
sto
ck
to another, less celebrated, tool of astronomical
discovery – the spectrograph.
The realisation that light could harbour
information about celestial objects came thanks
to the work of the German glass-maker Joseph von
Fraunhofer. In 1814 he dispersed the Sun’s light
into a rainbow of colours – known as a spectrum
– discovering numerous dark absorption lines (see
‘The Science of Spectra’, right) that were later found
to betray the composition of our star. With the
subsequent development of spectroscopes to view –
and spectrographs to record – celestial spectra and
the lines they contained, astronomers had a means
to examine the make-up of stars.
The next generationEver since those early days, spectroscopy and
the spectrograph have been an integral part of
astronomical research, giving astronomers insights
into not just the composition of faraway bodies
but also their temperature, distance and even
movements. Now, two centuries after Fraunhofer’s
studies, astronomers are readying a new generation
of spectrographs to explore the Universe, the likes
of which have never been seen before.
Under the bright lights of the cavernous High Bay
clean room at NASA’s Goddard Space Flight Center
in Maryland, the James Webb Space Telescope is
slowly taking shape. Yellow scissor fences carefully
partition off areas of the immaculate, white-foored
room where instruments and other structures rest
on substantial support stands. High above, on an
enormous gantry, each of the telescope’s 18 primary
mirror segments sit protected within huge polished
metal containers. Gradually, the components
are being meticulously tested and, eventually,
integrated into the telescope’s skeleton, ahead of
its planned launch in 2018.
Sitting in its own corner of the Goddard clean
room, NIRSpec – the Near-Infrared Spectrograph
– is just one of the four instruments that will
fy on James Webb. As with all of the telescope’s
instruments, it will focus on observing the Universe
at infrared wavelengths. To understand why, you
only need to look at the work of James Webb’s
forebear, the Hubble Space Telescope.
Hubble has excelled at studying faraway galaxies
as well as extrasolar planets and how they form
within vast clouds of dust and gas. But to peer
Þ Lines in the Sun’s spectrum show which wavelengths of light have been absorbed by its atmosphere
Joseph von Fraunhofer, left, demonstrates his spectrocope in Munich in 1814
>
stellar spectroscopy april 75
skyatnightmagazine.com 2014
The science of spectraKey to understanding why spectroscopy is such a formidable tool for astronomers is knowing what creates the features of a spectrum. You can think of the lines in astronomical spectra as celestial fngerprints, in that they can help scientists work out what atoms and molecules created them.
These ‘fngerprints’ come in two forms, absorption lines and emission lines. Let’s look at absorption lines frst. Objects such as stars create what are known as continuum spectra. If we think about just the visible-light portion of the electromagnetic spectrum, a continuum spectrum looks like an unbroken rainbow of
colours from violet at one end to red at the other. Yet when we look at stars within this continuum we see dark lines, like those that Fraunhofer saw in the spectrum of the Sun. These are absorption lines. They’re made when photons of light passing through the star’s atmosphere interact with electrons in the gases there. These electrons can absorb the photons’ energy, removing certain wavelengths from the continuum. Which ones are removed depends on the atoms or molecules present. By identifying the dark lines in a spectrum astronomers can determine the composition of the star’s atmosphere.
In emission lines you see the opposite. For example, photons from a bright star may be causing a nearby nebula to glow. When this happens, the photons from the star give energy to, or ‘excite’, the electrons in the nebula’s gases. Those electrons will eventually settle down and they do this by releasing energy in the form of a photon of light. The wavelengths of the photons emitted are indicative of the atom or molecule that is glowing. If you could observe the light from the nebula with a spectroscope, you’d see a series of thin, bright lines of different colours – these are emission lines.
STARNEBULA
Star’s atmosphere
Hot bright stars
ABSORPTION LINES EMISSION LINES
further out into the Universe and deeper into
nebulae you need to see the cosmos at much longer
wavelengths, says NIRSpec instrument scientist
James Muzerolle. “Near-infrared and mid-infrared
observations allow us to penetrate the dusty
environments that are very important for studying
star and planet formation,” he says.
Using NIRSpec, astronomers will also be able to
study light from some of the most distant, and thus
earliest, galaxies. Light that has been stretched as it
travelled across the expanding Universe. “The light
that we’ll measure at our telescope will be light that
was originally mostly in the ultraviolet [section of
the spectrum] that’s been redshifted into the near-
infrared,” explains Muzerolle. “You have to be able
to look at longer wavelengths in the near-infrared
[region] in order to detect [the galaxies] at all.”
Like all spectrographs, NIRSpec will break
down the light of celestial objects into spectra Þ NIRSpec’s flter carousel sits in the centre of the device and holds eight light flters>
stellar spectroscopy april 75
skyatnightmagazine.com 2014
The science of spectraKey to understanding why spectroscopy is such a formidable tool for astronomers is knowing what creates the features of a spectrum. You can think of the lines in astronomical spectra as celestial fngerprints, in that they can help scientists work out what atoms and molecules created them.
These ‘fngerprints’ come in two forms, absorption lines and emission lines. Let’s look at absorption lines frst. Objects such as stars create what are known as continuum spectra. If we think about just the visible-light portion of the electromagnetic spectrum, a continuum spectrum looks like an unbroken rainbow of
colours from violet at one end to red at the other. Yet when we look at stars within this continuum we see dark lines, like those that Fraunhofer saw in the spectrum of the Sun. These are absorption lines. They’re made when photons of light passing through the star’s atmosphere interact with electrons in the gases there. These electrons can absorb the photons’ energy, removing certain wavelengths from the continuum. Which ones are removed depends on the atoms or molecules present. By identifying the dark lines in a spectrum astronomers can determine the composition of the star’s atmosphere.
In emission lines you see the opposite. For example, photons from a bright star may be causing a nearby nebula to glow. When this happens, the photons from the star give energy to, or ‘excite’, the electrons in the nebula’s gases. Those electrons will eventually settle down and they do this by releasing energy in the form of a photon of light. The wavelengths of the photons emitted are indicative of the atom or molecule that is glowing. If you could observe the light from the nebula with a spectroscope, you’d see a series of thin, bright lines of different colours – these are emission lines.
STARNEBULA
Star’s atmosphere
Hot bright stars
ABSORPTION LINES EMISSION LINES
further out into the Universe and deeper into
nebulae you need to see the cosmos at much longer
wavelengths, says NIRSpec instrument scientist
James Muzerolle. “Near-infrared and mid-infrared
observations allow us to penetrate the dusty
environments that are very important for studying
star and planet formation,” he says.
Using NIRSpec, astronomers will also be able to
study light from some of the most distant, and thus
earliest, galaxies. Light that has been stretched as it
travelled across the expanding Universe. “The light
that we’ll measure at our telescope will be light that
was originally mostly in the ultraviolet [section of
the spectrum] that’s been redshifted into the near-
infrared,” explains Muzerolle. “You have to be able
to look at longer wavelengths in the near-infrared
[region] in order to detect [the galaxies] at all.”
Like all spectrographs, NIRSpec will break
down the light of celestial objects into spectra Þ NIRSpec’s flter carousel sits in the centre of the device and holds eight light flters>
76
skyatnightmagazine.com 2014
whose features, such as dark absorption lines, can
tell astronomers much about what they’re looking
at. But NIRSpec’s great strength will be its ability to
carry out what is known as multi-object spectroscopy.
“With a traditional spectrograph you have one slit
that, generally speaking, is only big enough to put
onto one object, like one star. You have to go one at
a time to build up a large
sample of spectroscopy of
many different stars,”
explains Muzerolle.
NIRSpec will be able to
capture the spectra of
around a hundred celestial
objects, such as stars or faint galaxies, in one shot.
It’s able to do this thanks to an advanced piece of
technology known as a micro-shutter array.
Shut out the light“Even on the ground there are not a lot of
instruments that have used this kind of
technology,” says Muzerolle. In essence, the micro-
shutter array’s role is to purposely block out large
parts of NIRSpec’s feld of view. Light from the
JWST’s 6.5m mirror will be fed into NIRSpec via a
complex system of optics. But before it reaches the
instrument’s grating, which spreads the light into
a spectrum, it will frst encounter the array. Here a
panel of roughly a quarter of a million microscopic
doors, or ‘shutters’, can be programmed to remain
either open or closed while the instrument is
making its observations. The result being that light
will only be let through from a select few parts
of the instrument’s feld of view – the parts that
contain the objects the
astronomers specifcally
want spectra of.
“For example if you
want to take spectroscopy
of stars in a cluster you
point the telescope at the
cluster and then open the shutters at the positions
of the stars that you’re interested in,” explains
Muzerolle. “All of the rest of the shutters [would
be] closed so that you don’t get any background or
other contaminating light getting through.”
The light going through the open shutters
from the chosen targets will then fall onto one of
NIRSpec’s gratings, which will produce spectra
that can be imaged by the instrument’s extremely
sensitive camera chips. This image, of up to a
hundred tiny infrared ‘rainbows’, will then be
beamed back to Earth where it can be analysed
by astronomers on the ground.
“NIRSpec will be able to capture the spectra of around a hundred
celestial objects in one shot”
Þ The JWST will see the Universe in infrared, allowing it to look back at the earliest galaxies
>
>na
sa
, th
ink
sto
ck
, n
asa
/es
a, n
asa
/Jpl
-ca
ltec
h/m
ali
n s
pac
e sc
ien
ce
syste
ms,
eso
/l.
ca
lça
da
, n
asa
/Jpl
-ca
ltec
h/s
si
76
skyatnightmagazine.com 2014
whose features, such as dark absorption lines, can
tell astronomers much about what they’re looking
at. But NIRSpec’s great strength will be its ability to
carry out what is known as multi-object spectroscopy.
“With a traditional spectrograph you have one slit
that, generally speaking, is only big enough to put
onto one object, like one star. You have to go one at
a time to build up a large
sample of spectroscopy of
many different stars,”
explains Muzerolle.
NIRSpec will be able to
capture the spectra of
around a hundred celestial
objects, such as stars or faint galaxies, in one shot.
It’s able to do this thanks to an advanced piece of
technology known as a micro-shutter array.
Shut out the light“Even on the ground there are not a lot of
instruments that have used this kind of
technology,” says Muzerolle. In essence, the micro-
shutter array’s role is to purposely block out large
parts of NIRSpec’s feld of view. Light from the
JWST’s 6.5m mirror will be fed into NIRSpec via a
complex system of optics. But before it reaches the
instrument’s grating, which spreads the light into
a spectrum, it will frst encounter the array. Here a
panel of roughly a quarter of a million microscopic
doors, or ‘shutters’, can be programmed to remain
either open or closed while the instrument is
making its observations. The result being that light
will only be let through from a select few parts
of the instrument’s feld of view – the parts that
contain the objects the
astronomers specifcally
want spectra of.
“For example if you
want to take spectroscopy
of stars in a cluster you
point the telescope at the
cluster and then open the shutters at the positions
of the stars that you’re interested in,” explains
Muzerolle. “All of the rest of the shutters [would
be] closed so that you don’t get any background or
other contaminating light getting through.”
The light going through the open shutters
from the chosen targets will then fall onto one of
NIRSpec’s gratings, which will produce spectra
that can be imaged by the instrument’s extremely
sensitive camera chips. This image, of up to a
hundred tiny infrared ‘rainbows’, will then be
beamed back to Earth where it can be analysed
by astronomers on the ground.
“NIRSpec will be able to capture the spectra of around a hundred
celestial objects in one shot”
Þ The JWST will see the Universe in infrared, allowing it to look back at the earliest galaxies
>
>na
sa
, th
ink
sto
ck
, n
asa
/es
a,
na
sa
/Jpl
-ca
ltec
h/m
ali
n s
pac
e sc
ien
ce
syste
ms,
eso
/l.
ca
lça
da
, n
asa
/Jpl
-ca
ltec
h/s
si
stellar spectroscopy april 77
skyatnightmagazine.com 2014
The Cosmic Origins Spectrograph The Cosmic Origins Spectrograph (COS) sits inside the Hubble Space Telescope. It was ftted to the orbiting observatory in 2009, when Hubble was visited by astronauts on Space Shuttle Atlantis. As its name suggests, the instrument is used to explore how various objects in the Universe, including galaxies and stars, came into being. In particular, COS has been used to examine the large-scale network of galaxies and gas present in space, known as the ‘cosmic web’.
insTrumenTs of discoverya number of missions have used spectroscopy to deliver insights into the workings of the Universe
ChemCamNASA’s Curiosity rover certainly lives up to its original name – the Mars Science Laboratory. It is covered with cameras and scientifc instruments, including the ChemCam spectrometer. ChemCam works by zapping a target, such as an interesting rock, with a powerful laser. The plasma released is then analysed to see what the target is made of. The range of the laser is such that the instrument can study features that are 7m away from the rover.
HARPSThe High Accuracy Radial Velocity Planet Searcher (HARPS) is mounted on the ESO 3.6m Telescope at the La Silla Observatory in Chile. From this mountaintop site, with pristine skies, HARPS is used to hunt for planets orbiting around distant stars. By looking for tell-tale movements of the lines in the spectra of these faraway stars, scientists are able to use the instrument to infer the presence of extrasolar worlds.
VIMSThe Cassini mission to Saturn has been exploring the ringed planet and its moons since 2004. On board the spacecraft are cameras, spectrometers and other scientifc instruments that have given us incredible insights into this remarkable planetary system. The Visible and Infrared Mapping Spectrometer (VIMS) has studied the icy jets coming from Saturn’s moon Enceladus, the hydrocarbon lakes on the planet’s largest moon Titan and weather in the gas giant’s atmosphere.
stellar spectroscopy april 77
skyatnightmagazine.com 2014
The Cosmic Origins Spectrograph The Cosmic Origins Spectrograph (COS) sits inside the Hubble Space Telescope. It was ftted to the orbiting observatory in 2009, when Hubble was visited by astronauts on Space Shuttle Atlantis. As its name suggests, the instrument is used to explore how various objects in the Universe, including galaxies and stars, came into being. In particular, COS has been used to examine the large-scale network of galaxies and gas present in space, known as the ‘cosmic web’.
insTrumenTs of discoverya number of missions have used spectroscopy to deliver insights into the workings of the Universe
ChemCamNASA’s Curiosity rover certainly lives up to its original name – the Mars Science Laboratory. It is covered with cameras and scientifc instruments, including the ChemCam spectrometer. ChemCam works by zapping a target, such as an interesting rock, with a powerful laser. The plasma released is then analysed to see what the target is made of. The range of the laser is such that the instrument can study features that are 7m away from the rover.
HARPSThe High Accuracy Radial Velocity Planet Searcher (HARPS) is mounted on the ESO 3.6m Telescope at the La Silla Observatory in Chile. From this mountaintop site, with pristine skies, HARPS is used to hunt for planets orbiting around distant stars. By looking for tell-tale movements of the lines in the spectra of these faraway stars, scientists are able to use the instrument to infer the presence of extrasolar worlds.
VIMSThe Cassini mission to Saturn has been exploring the ringed planet and its moons since 2004. On board the spacecraft are cameras, spectrometers and other scientifc instruments that have given us incredible insights into this remarkable planetary system. The Visible and Infrared Mapping Spectrometer (VIMS) has studied the icy jets coming from Saturn’s moon Enceladus, the hydrocarbon lakes on the planet’s largest moon Titan and weather in the gas giant’s atmosphere.
78 stellar spectroscopy april
skyatnightmagazine.com 2014
ABOUT THE WRITER
Will Gater is an astronomy writer and journalist. the author of several astronomy books, he regularly appears tV and radio. Find him on twitter: @willgater
In capturing spectra of many stars at once,
NIRSpec will allow astronomers to gather large
samples of data that should shine a light on the
processes at work in star and planet formation.
“From a statistical standpoint, this will really
advance the feld by a considerable amount,” says
Muzerolle. When the instrument surveys the most
distant realms of the Universe it should also tell us
more about how some of the frst galaxies were born
and how they evolved.
In doing so it will give
astronomers a glimpse
of the Universe as it was
“a few hundred million
years after the Big Bang”,
says Muzerolle. “We
hope that we’ll be able
to see many galaxies
that are in the process
of forming, of collecting their initial material,” he
adds. NIRSpec isn’t the only spectrograph that will
be operating on James Webb though.
A second pair of eyesMIRI, the Mid-Infrared Instrument, will study
many of the objects that NIRSpec will. But
because it observes in the longer wavelength,
mid-infrared region of the electromagnetic
spectrum it will also be able to examine some
phenomena that NIRSpec can’t. “With MIRI
we’ll be able to study a whole range of astronomical
objects from inside our own Solar System to
the furthest reaches of the observable Universe,”
says Sarah Kendrew, one of the astronomers who
worked on MIRI. “It is particularly sensitive to
colder, dustier environments, the sort that we
currently struggle to observe with the Hubble Space
Telescope. Discs of dust around newly formed stars,
for example, will be excellent targets for MIRI. As
those are the birthplaces of planets, that’s a
particularly exciting area of research.”
Spectrographs have
been at the very heart
of astronomy for two
centuries. And one can
only imagine the awe
with which Fraunhofer
might regard modern
instruments, like MIRI
and NIRSpec, if he could
see them in their clean
room today. Two hundred years ago his pioneering
work revolutionised our understanding of the
Universe. Now the legacy of that work is preparing
to launch into space to start a new, and equally
ground-breaking, revolution of its own.
“MIRI will be able to study a range of objects from inside our
own Solar System to the furthest reaches of the Universe”
Þ MIRI will be used to see what’s inside the dust clouds around newly formed stars
S
>
ala
my
78 stellar spectroscopy april
skyatnightmagazine.com 2014
ABOUT THE WRITER
Will Gater is an astronomy writer and journalist. the author of several astronomy books, he regularly appears tV and radio. Find him on twitter: @willgater
In capturing spectra of many stars at once,
NIRSpec will allow astronomers to gather large
samples of data that should shine a light on the
processes at work in star and planet formation.
“From a statistical standpoint, this will really
advance the feld by a considerable amount,” says
Muzerolle. When the instrument surveys the most
distant realms of the Universe it should also tell us
more about how some of the frst galaxies were born
and how they evolved.
In doing so it will give
astronomers a glimpse
of the Universe as it was
“a few hundred million
years after the Big Bang”,
says Muzerolle. “We
hope that we’ll be able
to see many galaxies
that are in the process
of forming, of collecting their initial material,” he
adds. NIRSpec isn’t the only spectrograph that will
be operating on James Webb though.
A second pair of eyesMIRI, the Mid-Infrared Instrument, will study
many of the objects that NIRSpec will. But
because it observes in the longer wavelength,
mid-infrared region of the electromagnetic
spectrum it will also be able to examine some
phenomena that NIRSpec can’t. “With MIRI
we’ll be able to study a whole range of astronomical
objects from inside our own Solar System to
the furthest reaches of the observable Universe,”
says Sarah Kendrew, one of the astronomers who
worked on MIRI. “It is particularly sensitive to
colder, dustier environments, the sort that we
currently struggle to observe with the Hubble Space
Telescope. Discs of dust around newly formed stars,
for example, will be excellent targets for MIRI. As
those are the birthplaces of planets, that’s a
particularly exciting area of research.”
Spectrographs have
been at the very heart
of astronomy for two
centuries. And one can
only imagine the awe
with which Fraunhofer
might regard modern
instruments, like MIRI
and NIRSpec, if he could
see them in their clean
room today. Two hundred years ago his pioneering
work revolutionised our understanding of the
Universe. Now the legacy of that work is preparing
to launch into space to start a new, and equally
ground-breaking, revolution of its own.
“MIRI will be able to study a range of objects from inside our
own Solar System to the furthest reaches of the Universe”
Þ MIRI will be used to see what’s inside the dust clouds around newly formed stars
S
>
ala
my
*These extra items will be available with various issues in 2014 depending on subscription start date. After your fi rst 12 issues, you will then go on to pay £38.40 every 12 issues by Direct Debit,saving 20%. This offer is only open to new UK Direct Debit customers subscribing to Gardeners’ World Magazine. The closing date for this offer is April 30th 2014. You may cancel at any time and receive a full refund on any outstanding issues by contacting your bank or building society. Written confi rmation may also be required. Prices are discounted from the full UK subscription price and include P & P. Standard UK subscription price is £48, Europe and Republic of Ireland is £63.60 and Rest of the World is £80.40. Calling the 0844 848 9707 order number from a BT landline will cost no more than 5p per minute. Calls from mobiles and other providers may vary. Please note enquiry lines are open 9am-6pm.
SAVE 50% when you subscribe today!
Never miss an inspiring issue of
BBC Gardeners’ World Magazine.
Subscribe today by Direct Debit and
save 50% of the cover price, paying
just £24 for 12 issues. This great-value
subscription of er will bring you
practical, trustworthy and expert
advice to help you work wonders
over the coming months.Subscribe today!
Just £24 for 12 issues
I Exclusive subscriber-only of ers and invitations to events
I Extra discounts on plant of ers
I Quarterly newsletter full of gardening of ers and events
I Delivery direct to your door
I Your own subscriber edition with exclusive cover and content in every issue
PLUS When you subscribe, you’ll become a member
of the BBC Gardeners’ World Magazine Subscriber Club.
Enjoy many benef ts including:
Extras FREE with this yearÕs magazine*:
I 2-for-1 Gardens to Visit Card and Guide I Small Garden Handbook I 2015 BBC Gardeners’ World Magazine
calendar, and more…
To celebrate spring we are of ering a whole year’s worth
of gardening advice for only £24 – that’s just £2 per issue
A subscription to BBC Gardeners’ World Magazine will help you appreciate your garden in the day and the Sky at Night
2 EASY WAYS TO SUBSCRIBE
Visit www.buysubscriptions.com/gardenersworld/GWXSN414
Call 0844 848 9707 and quote code GWXSN414 (Lines open Mon to Fri 8am-8pm and Sat 9am-1pm)
*These extra items will be available with various issues in 2014 depending on subscription start date. After your fi rst 12 issues, you will then go on to pay £38.40 every 12 issues by Direct Debit,saving 20%. This offer is only open to new UK Direct Debit customers subscribing to Gardeners’ World Magazine. The closing date for this offer is April 30th 2014. You may cancel at any time and receive a full refund on any outstanding issues by contacting your bank or building society. Written confi rmation may also be required. Prices are discounted from the full UK subscription price and include P & P. Standard UK subscription price is £48, Europe and Republic of Ireland is £63.60 and Rest of the World is £80.40. Calling the 0844 848 9707 order number from a BT landline will cost no more than 5p per minute. Calls from mobiles and other providers may vary. Please note enquiry lines are open 9am-6pm.
SAVE 50% when you subscribe today!
Never miss an inspiring issue of
BBC Gardeners’ World Magazine.
Subscribe today by Direct Debit and
save 50% of the cover price, paying
just £24 for 12 issues. This great-value
subscription of er will bring you
practical, trustworthy and expert
advice to help you work wonders
over the coming months.Subscribe today!
Just £24 for 12 issues
I Exclusive subscriber-only of ers and invitations to events
I Extra discounts on plant of ers
I Quarterly newsletter full of gardening of ers and events
I Delivery direct to your door
I Your own subscriber edition with exclusive cover and content in every issue
PLUS When you subscribe, you’ll become a member
of the BBC Gardeners’ World Magazine Subscriber Club.
Enjoy many benef ts including:
Extras FREE with this yearÕs magazine*:
I 2-for-1 Gardens to Visit Card and Guide I Small Garden Handbook I 2015 BBC Gardeners’ World Magazine
calendar, and more…
To celebrate spring we are of ering a whole year’s worth
of gardening advice for only £24 – that’s just £2 per issue
A subscription to BBC Gardeners’ World Magazine will help you appreciate your garden in the day and the Sky at Night
2 EASY WAYS TO SUBSCRIBE
Visit www.buysubscriptions.com/gardenersworld/GWXSN414
Call 0844 848 9707 and quote code GWXSN414 (Lines open Mon to Fri 8am-8pm and Sat 9am-1pm)
Pete Lawrence reveals his secrets to creating a frst-class lunar mosaic – from capturing the raw data to completion
THE MOONmosaicing
The Moon is a fascinating object to
both observe and image. The ever-
changing shadows crossing the
lunar surface make each and every
Moon session unique and interesting.
At roughly 0.5º across, it is relatively easy to
photograph the entire lunar disc in one go with
a DSLR camera, but this won’t bring out any
intricate detail. A telescope ftted with a high
frame rate camera allows you to get closer,
especially at high magnifcation. This typically
results in an image that shows more detail but
covers a smaller area of the Moon.
If you want highly detailed images of the
entire lunar disc, you need to use a technique
known as ‘mosaicing’. This is the process of taking
a number of zoomed-in shots and joining them
together. The ultimate goal is to produce a high-
resolution image of the whole lunar disc. Over
the next few pages, we take you through all the
steps necessary to produce one from scratch.
ABOUT THE WRITER
Pete Lawrence is an expert imager. Each month, he tells us about a new lunar target in our Moonwatch column – fnd it in the Sky Guide.
If you’re inspired by Pete’s effort, or think you could do the better, why not enter 2014’s Astronomy Photographer of the Year competition? Among the seven categories and prizes being contested is ‘Our Solar System’, for which the judges are looking for images that show the best of our cosmic backyard. For full details on how to sign up, the rules and how to submit your images, visit the competition website. www.rmg.co.uk/astrophoto
Pete Lawrence reveals his secrets to creating a frst-class lunar mosaic – from capturing the raw data to completion
THE MOONmosaicing
The Moon is a fascinating object to
both observe and image. The ever-
changing shadows crossing the
lunar surface make each and every
Moon session unique and interesting.
At roughly 0.5º across, it is relatively easy to
photograph the entire lunar disc in one go with
a DSLR camera, but this won’t bring out any
intricate detail. A telescope ftted with a high
frame rate camera allows you to get closer,
especially at high magnifcation. This typically
results in an image that shows more detail but
covers a smaller area of the Moon.
If you want highly detailed images of the
entire lunar disc, you need to use a technique
known as ‘mosaicing’. This is the process of taking
a number of zoomed-in shots and joining them
together. The ultimate goal is to produce a high-
resolution image of the whole lunar disc. Over
the next few pages, we take you through all the
steps necessary to produce one from scratch.
ABOUT THE WRITER
Pete Lawrence is an expert imager. Each month, he tells us about a new lunar target in our Moonwatch column – fnd it in the Sky Guide.
If you’re inspired by Pete’s effort, or think you could do the better, why not enter 2014’s Astronomy Photographer of the Year competition? Among the seven categories and prizes being contested is ‘Our Solar System’, for which the judges are looking for images that show the best of our cosmic backyard. For full details on how to sign up, the rules and how to submit your images, visit the competition website. www.rmg.co.uk/astrophoto
The author’s own mosaic of the waxing gibbous Moon; it is made
up of a staggering 213 panes PEtE L
aw
rEn
cEThe author’s own mosaic of the
waxing gibbous Moon; it is made up of a staggering 213 panes P
EtE L
aw
rEn
cE
1skyatnightmagazine.com 2014
Before you can create a mosaic, you
need detailed pictures. a mono high frame
rate camera is really the best tool for the job,
allowing you to record a short video of each
‘pane’ (segment of the lunar surface) as an
aVI fle, the individual frames of which can
be stacked into a still image later. If your
camera doesn’t have an infrared-blocking
flter built-in, consider attaching an infrared-
pass flter. Doing so can reduce the effects
of poor seeing. alternatively, try a red flter.
Moving across the lunar surface in
overlapping panels is something that sounds
easy to do, but there are pitfalls. The higher PEtE
La
wrEn
cE x
4, stE
vE m
arsh
Þ Follow the surface horizontally; higher magnifcation increases the number of panes but the method stays the same
the magnifcation you use, for instance, the
easier it is to get lost and miss a bit out; this
is a common frustration when starting out.
It pays to be realistic in terms of image scale.
If you’re experimenting with mosaics for
the frst time, capture a small number of
panes to start with so you can get a feel of
what’s what. Image scale can be adjusted
using optical amplifers such as Barlow
lenses, but aim to keep your scope’s overall
focal ratio somewhere between f/15 and f/45.
only go higher if the seeing gets really good.
a driven, equatorially mounted scope is
ideal. check camera alignment by slewing
in right ascension and rotating the camera
so that features move parallel to the bottom
edge of the frame. finally, focus your setup.
An equatorial setup is the most useful mount for mosaicing
caPTURing THE MOONRemembering a few simple rules will help you to capture a lunar mosaic without any gaps
Start
Finish
overlap
over
lap
Area of Moon visible (pane)
þ High frame rate cameras are the
best choice for lunar mosaicing
Use the features at the bottom of the frst row of frames as a guide for lining up the next row
Use features at the leading edge of the frame as a guide for the next frame
1skyatnightmagazine.com 2014
Before you can create a mosaic, you
need detailed pictures. a mono high frame
rate camera is really the best tool for the job,
allowing you to record a short video of each
‘pane’ (segment of the lunar surface) as an
aVI fle, the individual frames of which can
be stacked into a still image later. If your
camera doesn’t have an infrared-blocking
flter built-in, consider attaching an infrared-
pass flter. Doing so can reduce the effects
of poor seeing. alternatively, try a red flter.
Moving across the lunar surface in
overlapping panels is something that sounds
easy to do, but there are pitfalls. The higher PEtE
La
wrEn
cE x
4,
stE
vE m
arsh
Þ Follow the surface horizontally; higher magnifcation increases the number of panes but the method stays the same
the magnifcation you use, for instance, the
easier it is to get lost and miss a bit out; this
is a common frustration when starting out.
It pays to be realistic in terms of image scale.
If you’re experimenting with mosaics for
the frst time, capture a small number of
panes to start with so you can get a feel of
what’s what. Image scale can be adjusted
using optical amplifers such as Barlow
lenses, but aim to keep your scope’s overall
focal ratio somewhere between f/15 and f/45.
only go higher if the seeing gets really good.
a driven, equatorially mounted scope is
ideal. check camera alignment by slewing
in right ascension and rotating the camera
so that features move parallel to the bottom
edge of the frame. finally, focus your setup.
An equatorial setup is the most useful mount for mosaicing
caPTURing THE MOONRemembering a few simple rules will help you to capture a lunar mosaic without any gaps
Start
Finish
overlap
over
lap
Area of Moon visible (pane)
þ High frame rate cameras are the
best choice for lunar mosaicing
Use the features at the bottom of the frst row of frames as a guide for lining up the next row
Use features at the leading edge of the frame as a guide for the next frame
2
making a lunar mosaic april 83
skyatnightmagazine.com 2014
There are various ways to move across
the Moon, but imaging in horizontal
strips with lots of overlap is best. a good
overlap is typically 20-25 per cent. When
lining up your frst pane, make a note of
features close to the corners of the frame
and use these as guides when positioning
for the next one.
It’s good practice to image the strips in
the same direction, moving back to the
same starting side of the Moon between
strips. use features in the frst strip of panes
to make sure your vertical adjustment
gives plenty of overlap. a rough sketch of
the feature in each frame can help. If you
lose track, wind back to the last place you
know you defnitely imaged. It’s better to
risk duplication than a gap!
The nexT sTep is to process each aVI
fle to produce one still image, ready
for assembly into the fnal mosaic.
for a large mosaic containing many
individual panes this can be a daunting
and tedious task, but there are ways
to speed things up.
The frst processing step is to analyse,
register and stack the frames in each
aVI fle. There are various good (not to
mention, free) computer programs that
can do this for you automatically, among
them registax, autostakkert! and
avistack. for this project we’ll be using
avistack to take care of the bulk of the
processing and registax to perform
wavelet sharpening on the results.
The analysis step determines the
quality of each still frame and then
ranks them in order of how good they
are. a user-set quality threshold then
determines how many of the frames
are used. The frames that are above
the threshold are ‘registered’ (aligned)
to one another. These are then
‘stacked’ (averaged) to produce
a fnal image.
The higher the quality
threshold, the fewer frames
will ultimately go into the
stack. This will result in the
sharpest output, but with less
frames to average, noise is
more noticeable. set the quality
threshold lower and there will
be more frames to average,
resulting in a smoother, less
noisy result. however, using
lower quality frames reduces
overall image sharpness.
It’s a good idea to perform
a number of test runs using
avistack if you’re not familiar
with the program. There are a
lot of parameters and settings
that can be confgured; these are
shown in a separate window and can
be viewed by expanding the tree list.
Double clicking on a parameter section,
for example ‘frame selection’, will bring
point your scope at the brightest part of
the Moon and adjust the camera’s gain and
exposure so peak saturation is around 90
per cent. you should be able to leave this
alone. of course, you can adjust the exposure
levels for each frame if you want, but this
is more time consuming and requires
greater effort when it comes to stitching
your panes together; the advantage is less
noise in dark regions and extra navigational
detail when crossing seemingly featureless
areas such as the lunar seas.
What you will need to do during a long
mosaicing run is refocus often. This is
essential to prevent defocusing caused by
temperature variations. a 12V camping
hairdryer is also invaluable for removing
moisture from dewed-up optics during
long runs. Two fnal tips: mosaic captures
typically take up lots of computer hard
disk space, so make sure you have plenty
free; and plan ahead to make sure the
Moon doesn’t disappear behind by a
neighbouring tree or rooftop part-way
through your imaging session.
Þ You’ll need fewer panes to complete your mosaic at f/15, but at f/45 you’ll get more detail
Single pane at f/15
Single pane at f/45Þ Lining up your panes with a generous overlap will lessen the chances of missing a piece
PRocessing THE MOONNow that you’ve captured your panes as movie fles it’s time to turn them into high-resolution images
up a control window allowing you to
adjust the settings for that section. you
can toggle between automatic and
manual processing by clicking on
Þ Quality analysis determines which frames will give you the best results for each pane
>
2
making a lunar mosaic april 83
skyatnightmagazine.com 2014
There are various ways to move across
the Moon, but imaging in horizontal
strips with lots of overlap is best. a good
overlap is typically 20-25 per cent. When
lining up your frst pane, make a note of
features close to the corners of the frame
and use these as guides when positioning
for the next one.
It’s good practice to image the strips in
the same direction, moving back to the
same starting side of the Moon between
strips. use features in the frst strip of panes
to make sure your vertical adjustment
gives plenty of overlap. a rough sketch of
the feature in each frame can help. If you
lose track, wind back to the last place you
know you defnitely imaged. It’s better to
risk duplication than a gap!
The nexT sTep is to process each aVI
fle to produce one still image, ready
for assembly into the fnal mosaic.
for a large mosaic containing many
individual panes this can be a daunting
and tedious task, but there are ways
to speed things up.
The frst processing step is to analyse,
register and stack the frames in each
aVI fle. There are various good (not to
mention, free) computer programs that
can do this for you automatically, among
them registax, autostakkert! and
avistack. for this project we’ll be using
avistack to take care of the bulk of the
processing and registax to perform
wavelet sharpening on the results.
The analysis step determines the
quality of each still frame and then
ranks them in order of how good they
are. a user-set quality threshold then
determines how many of the frames
are used. The frames that are above
the threshold are ‘registered’ (aligned)
to one another. These are then
‘stacked’ (averaged) to produce
a fnal image.
The higher the quality
threshold, the fewer frames
will ultimately go into the
stack. This will result in the
sharpest output, but with less
frames to average, noise is
more noticeable. set the quality
threshold lower and there will
be more frames to average,
resulting in a smoother, less
noisy result. however, using
lower quality frames reduces
overall image sharpness.
It’s a good idea to perform
a number of test runs using
avistack if you’re not familiar
with the program. There are a
lot of parameters and settings
that can be confgured; these are
shown in a separate window and can
be viewed by expanding the tree list.
Double clicking on a parameter section,
for example ‘frame selection’, will bring
point your scope at the brightest part of
the Moon and adjust the camera’s gain and
exposure so peak saturation is around 90
per cent. you should be able to leave this
alone. of course, you can adjust the exposure
levels for each frame if you want, but this
is more time consuming and requires
greater effort when it comes to stitching
your panes together; the advantage is less
noise in dark regions and extra navigational
detail when crossing seemingly featureless
areas such as the lunar seas.
What you will need to do during a long
mosaicing run is refocus often. This is
essential to prevent defocusing caused by
temperature variations. a 12V camping
hairdryer is also invaluable for removing
moisture from dewed-up optics during
long runs. Two fnal tips: mosaic captures
typically take up lots of computer hard
disk space, so make sure you have plenty
free; and plan ahead to make sure the
Moon doesn’t disappear behind by a
neighbouring tree or rooftop part-way
through your imaging session.
Þ You’ll need fewer panes to complete your mosaic at f/15, but at f/45 you’ll get more detail
Single pane at f/15
Single pane at f/45Þ Lining up your panes with a generous overlap will lessen the chances of missing a piece
PRocessing THE MOONNow that you’ve captured your panes as movie fles it’s time to turn them into high-resolution images
up a control window allowing you to
adjust the settings for that section. you
can toggle between automatic and
manual processing by clicking on
Þ Quality analysis determines which frames will give you the best results for each pane
>
84
skyatnightmagazine.com 2014
PEtE L
aw
rEn
cE x
10
STEP 3That’s your frst processed fle complete. The settings for this fle will be automatically used for the batch processing run. Click ‘Add movies’ and select all of the fles to be processed, then click ‘Open’. Finally, click ‘Batch processing’ and let the program run through each fle in turn, saving the results according to the settings you chose in the save stacked image box in the previous step.
the gear wheel icon below the
section header. setting the toggle
to ‘automatic processing’ lets avistack
make decisions for you, which can be
useful if you’re not initially sure what
you’re doing.
avistack has a great batch-processing
mode that can work on large numbers
of aVI fles unattended. The end result
is a single distilled image for each aVI
capture. Various output formats are
available but we recommend pnG as
this is a lossless format that many
editing programs and fle viewers can
easily display. other lossless fles can also
be used, but how easy they are to view
and manipulate may vary. avoid lossy
formats such as JpeG.
following the step-by-step guide below,
the initial process delivers results with
no sharpening. To the eye these will look
blurred, so to address this we’ll apply the
excellent wavelet sharpening function
within registax.
sharpening lunar images is something
that needs to be done with great care.
once you start to apply sharpening to an
image, it’s easy to get carried away and
push it just that little bit too far.
If in doubt, it’s a good idea to leave
the image up on your computer screen
and walk away from it for a while. When
you come back, your initial reaction
will be a good indicator as to whether
you’ve taken things too far. If you’re
creating your mosaic at low magnifcation,
a gentle tweak on the frst slider is all that’s
normally required.
STEP 1Load a single AVI into AviStack for processing. If you’re technically minded, choose ‘Settings’, ‘Processing’, ‘All manual’ from the main window menu. If not, select ‘All automatic’. Expand the ‘Save stacked image’ section and make sure ‘Manual processing’ is set; click on “Automatic processing” if shown. Expand ‘Post processing’ and select ‘Manual processing’. The four options below this should be deselected, as shown above.
STEP 4Once you have all the AviStack-processed PNG results, copy them all to a new folder, named something like ‘Wavelet-sharpened’. These are the fles we’ll edit in RegiStax; leaving the originals untouched means you can rework them at a later date – say if new software or more advanced techniques become available. Once you have your fnal results, the originals can be discarded if you need the disk space.
STEP 5Run RegiStax and click ‘Select’. Change ‘Files of type’ to match the format of the processed images (in our example, PNG). Load the frst image. With the Wavelet tab selected, click on the preview buttons to the right of the sliders to see which details will change. Use the slider that shows the fnest detail that isn’t just noise grain. Adjust the slider to sharpen the image to taste.
STEP 6Wavelet sharpen all of the images, saving each when done. Next, load the frst image into a layer-based editing program such as Photoshop or GIMP and crop off any unwanted edge artefacts. Estimate and adjust the canvas size so that it will hold all of the panes; don’t worry too much if you get the size wrong as it can be adjusted later. Select a black background for the new canvas area before you do this.
STEP 2Click on ‘Process fle’. When the ‘Save stacked image’ window appears – see right – select PNG as the fle type and defne the save folder. Make sure ‘Save parameters’ is ticked before you click on ‘Save’. Press ‘Cancel’ when the ‘Post processing’ window appears. Test the suitability of the result for wavelet sharpening – see step 5. If it is not, repeat and adjust parameter settings during a manual run using the help options to assist.
Add Movies(fle open)
Batch processing
Þ AVIs can be batch processed manually or automatically
prOcEssiNg – sTEp by sTEp
>
84
skyatnightmagazine.com 2014
PEtE L
aw
rEn
cE x
10
STEP 3That’s your frst processed fle complete. The settings for this fle will be automatically used for the batch processing run. Click ‘Add movies’ and select all of the fles to be processed, then click ‘Open’. Finally, click ‘Batch processing’ and let the program run through each fle in turn, saving the results according to the settings you chose in the save stacked image box in the previous step.
the gear wheel icon below the
section header. setting the toggle
to ‘automatic processing’ lets avistack
make decisions for you, which can be
useful if you’re not initially sure what
you’re doing.
avistack has a great batch-processing
mode that can work on large numbers
of aVI fles unattended. The end result
is a single distilled image for each aVI
capture. Various output formats are
available but we recommend pnG as
this is a lossless format that many
editing programs and fle viewers can
easily display. other lossless fles can also
be used, but how easy they are to view
and manipulate may vary. avoid lossy
formats such as JpeG.
following the step-by-step guide below,
the initial process delivers results with
no sharpening. To the eye these will look
blurred, so to address this we’ll apply the
excellent wavelet sharpening function
within registax.
sharpening lunar images is something
that needs to be done with great care.
once you start to apply sharpening to an
image, it’s easy to get carried away and
push it just that little bit too far.
If in doubt, it’s a good idea to leave
the image up on your computer screen
and walk away from it for a while. When
you come back, your initial reaction
will be a good indicator as to whether
you’ve taken things too far. If you’re
creating your mosaic at low magnifcation,
a gentle tweak on the frst slider is all that’s
normally required.
STEP 1Load a single AVI into AviStack for processing. If you’re technically minded, choose ‘Settings’, ‘Processing’, ‘All manual’ from the main window menu. If not, select ‘All automatic’. Expand the ‘Save stacked image’ section and make sure ‘Manual processing’ is set; click on “Automatic processing” if shown. Expand ‘Post processing’ and select ‘Manual processing’. The four options below this should be deselected, as shown above.
STEP 4Once you have all the AviStack-processed PNG results, copy them all to a new folder, named something like ‘Wavelet-sharpened’. These are the fles we’ll edit in RegiStax; leaving the originals untouched means you can rework them at a later date – say if new software or more advanced techniques become available. Once you have your fnal results, the originals can be discarded if you need the disk space.
STEP 5Run RegiStax and click ‘Select’. Change ‘Files of type’ to match the format of the processed images (in our example, PNG). Load the frst image. With the Wavelet tab selected, click on the preview buttons to the right of the sliders to see which details will change. Use the slider that shows the fnest detail that isn’t just noise grain. Adjust the slider to sharpen the image to taste.
STEP 6Wavelet sharpen all of the images, saving each when done. Next, load the frst image into a layer-based editing program such as Photoshop or GIMP and crop off any unwanted edge artefacts. Estimate and adjust the canvas size so that it will hold all of the panes; don’t worry too much if you get the size wrong as it can be adjusted later. Select a black background for the new canvas area before you do this.
STEP 2Click on ‘Process fle’. When the ‘Save stacked image’ window appears – see right – select PNG as the fle type and defne the save folder. Make sure ‘Save parameters’ is ticked before you click on ‘Save’. Press ‘Cancel’ when the ‘Post processing’ window appears. Test the suitability of the result for wavelet sharpening – see step 5. If it is not, repeat and adjust parameter settings during a manual run using the help options to assist.
Add Movies(fle open)
Batch processing
Þ AVIs can be batch processed manually or automatically
prOcEssiNg – sTEp by sTEp
>
3making a lunar mosaic april 85
skyatnightmagazine.com 2014
The excITInG parT of mosaicing is
building the fnal image. There are free
programs that can do this automatically,
including Microsoft’s excellent Image
composite editor (Ice). Building the
mosaic manually is a more time-consuming
process, but ultimately a rewarding
experience. Doing it yourself can also help
to avoid the errors that sometimes occur
when using automated programs.
If you followed our step-by-step guide
on the previous page, your base image
will contain a single fnished pane and
your canvas will be of suffcient size to
take the rest.
Load the next frame in the sequence
and draw a selection box slightly smaller
than the frame edge within it. apply a
5-10 pixel feather to the selection.
copy the selection and paste it into
the base image. use the arrow keys to
nudge the pane into alignment with
the lower image. Toggling the visibility
of the nudged layer on and off will help
you to line it up accurately.
small variations in tone between the
pasted and base images can normally be
dealt with by gently tweaking the curves
tool – you should apply the adjustment
to the centre of the curve. for larger
variations, raise or drop the brightness
of the image frst to get it closer to where
you want it, then use the curves tool to
carry out fne adjustments.
The feathered edges of the pasted
image pane should make any straight
edges hard to see. If some are still obvious,
set the eraser tool to 10 per cent strength
and gently rub it over any visible joins;
this should hide them.
for very large mosaics that stretch
your computer’s memory, assemble a
batch of panes and then save the layered
image to a fle called ‘mosaic-001’. flatten
the image and continue loading with the
next set of frames. When you get to a
similar stage as before, save as ‘mosaic-002’
and fatten. repeat until the whole mosaic
is complete. This technique means you
can go back and address any major
problems found at the end.
When done, fatten the image and save
to a fle name of your choice. a gentle
tweak of brightness or contrast, or a small
adjustment using the Levels and curves
tools, can help to fnish off your masterpiece.
It takes a bit of work to build such a mosaic
manually but once it’s done, the feeling of
satisfaction will be immense; that is unless
you’ve missed a bit of course!
sTiTching THE MOONAll the hard work you’ve put in up to this point is about to pay off with the best part, assembling the mosaic
Þ Align your panes by zooming in and nudging them into place with the arrow keys
Þ You may need to adjust brightness and contrast to blend adjacent panes together
Whether a full disc or a crescent, a lunar mosaic is one of the most rewarding
images you can produce
S
3making a lunar mosaic april 85
skyatnightmagazine.com 2014
The excITInG parT of mosaicing is
building the fnal image. There are free
programs that can do this automatically,
including Microsoft’s excellent Image
composite editor (Ice). Building the
mosaic manually is a more time-consuming
process, but ultimately a rewarding
experience. Doing it yourself can also help
to avoid the errors that sometimes occur
when using automated programs.
If you followed our step-by-step guide
on the previous page, your base image
will contain a single fnished pane and
your canvas will be of suffcient size to
take the rest.
Load the next frame in the sequence
and draw a selection box slightly smaller
than the frame edge within it. apply a
5-10 pixel feather to the selection.
copy the selection and paste it into
the base image. use the arrow keys to
nudge the pane into alignment with
the lower image. Toggling the visibility
of the nudged layer on and off will help
you to line it up accurately.
small variations in tone between the
pasted and base images can normally be
dealt with by gently tweaking the curves
tool – you should apply the adjustment
to the centre of the curve. for larger
variations, raise or drop the brightness
of the image frst to get it closer to where
you want it, then use the curves tool to
carry out fne adjustments.
The feathered edges of the pasted
image pane should make any straight
edges hard to see. If some are still obvious,
set the eraser tool to 10 per cent strength
and gently rub it over any visible joins;
this should hide them.
for very large mosaics that stretch
your computer’s memory, assemble a
batch of panes and then save the layered
image to a fle called ‘mosaic-001’. flatten
the image and continue loading with the
next set of frames. When you get to a
similar stage as before, save as ‘mosaic-002’
and fatten. repeat until the whole mosaic
is complete. This technique means you
can go back and address any major
problems found at the end.
When done, fatten the image and save
to a fle name of your choice. a gentle
tweak of brightness or contrast, or a small
adjustment using the Levels and curves
tools, can help to fnish off your masterpiece.
It takes a bit of work to build such a mosaic
manually but once it’s done, the feeling of
satisfaction will be immense; that is unless
you’ve missed a bit of course!
sTiTching THE MOONAll the hard work you’ve put in up to this point is about to pay off with the best part, assembling the mosaic
Þ Align your panes by zooming in and nudging them into place with the arrow keys
Þ You may need to adjust brightness and contrast to blend adjacent panes together
Whether a full disc or a crescent, a lunar mosaic is one of the most rewarding
images you can produce
S
UK
ADVERTISEMENT FEATURE
It is quite easy to become daunted by the vast array
of equipment that is available to today’s amateur
astronomers. Different makes, different models, different
sizes and optical arrangements – if you’re new to the
hobby, how do you make sense of all these details and fnd the
telescope that will show you the Universe?
The answer lies in buying from a specialist retailer –
somewhere that really knows what they’re talking about. Like
the retailers in this guide, they’ll have the practical knowledge
that will guide you towards the scope that won’t end up
gathering dust in a cupboard.
Today there are over 1,000 models of telescope to choose
from – refractors and refectors, Dobsonians and Newtonians,
Schmidt- and Maksutov-Cassegrains. And just as important as
the telescope is the mount it sits on; but do you go for equatorial
or altazimuth, manual or Go-To? And what about accessories
like eyepieces and fnderscopes?
That’s certainly a lot to consider before making a decision,
but a specialist retailer will help you make that decision, taking
important considerations like portability, construction and price
into account.
So if you need friendly, face-to-face advice and excellent
aftersales service, free from biased opinions, specialist
telescope retailers are the place to go for a helping hand
through the technical literature and tables of fgures. They’ll
help you fnd a scope that combines quality and convenience at
a price that’s right.
Find the right one for you: buy your
telescope from a specialist retailer
Retailer Guide
UK
ADVERTISEMENT FEATURE
It is quite easy to become daunted by the vast array
of equipment that is available to today’s amateur
astronomers. Different makes, different models, different
sizes and optical arrangements – if you’re new to the
hobby, how do you make sense of all these details and fnd the
telescope that will show you the Universe?
The answer lies in buying from a specialist retailer –
somewhere that really knows what they’re talking about. Like
the retailers in this guide, they’ll have the practical knowledge
that will guide you towards the scope that won’t end up
gathering dust in a cupboard.
Today there are over 1,000 models of telescope to choose
from – refractors and refectors, Dobsonians and Newtonians,
Schmidt- and Maksutov-Cassegrains. And just as important as
the telescope is the mount it sits on; but do you go for equatorial
or altazimuth, manual or Go-To? And what about accessories
like eyepieces and fnderscopes?
That’s certainly a lot to consider before making a decision,
but a specialist retailer will help you make that decision, taking
important considerations like portability, construction and price
into account.
So if you need friendly, face-to-face advice and excellent
aftersales service, free from biased opinions, specialist
telescope retailers are the place to go for a helping hand
through the technical literature and tables of fgures. They’ll
help you fnd a scope that combines quality and convenience at
a price that’s right.
Find the right one for you: buy your
telescope from a specialist retailer
Retailer Guide
ADVERTISEMENT FEATURE
Telescope House
01342 837610www.telescopehouse.com
sales@telescopehouse.com
Founded in 1785, Telescope House has been responsible for supplying many well-known Astronomers with telescopes and equipment. The late Sir Patrick Moore bought the majority of his telescopes from the company, including his very frst instrument. With a friendly showroom in Surrey, a number one ranked retail website and a service centre with fully qualifed staff, the company offers equipment from manufacturers such as Meade, Revelation, Coronado, Bresser, Skywatcher, Orion USA, TeleVue, Vixen and Explore Scientifc. Whether it’s advice on your frst telescope, to setting up advanced Astrophotography systems, the staff at Telescope House have a wealth of experience and instant access to the right stock to back it up.
TRinG AsTRonomy cenTRe
01442 822997 www.tringastro.co.uk
enquiries@tringastro.co.uk
At Tring Astronomy Centre we know that choosing the right equipment can be a minefeld, but we strongly believe that seeing telescopes in the fesh and talking to an expert in a relaxed environment can really help. That’s why we have a coffee machine, a fully stocked bicuit barrel, and 45+ telescopes on display. As well as representing leading brands such as Celestron, Sky-Watcher, Baader Planetarium, Altair Astro, Vixen, Opticron, AstroTrac, iOptron, Lunt, Starlight Instruments, ZW Optical and many more we also offer a hire service so you can even try before you buy! So what are you waiting for? Visit or contact Tring Astronomy Centre and lets talk Astronomy!
sHeRwoodsEstablished for over 60 years, we at Sherwoods are one of the Midlands leading suppliers of astronomical telescopes, binoculars and accessories. Through our website and showroom we are able to supply optics from some of the world’s leading optical manufacturers including Celestron, Skywatcher and Meade at some of the lowest prices in the UK. We offer a full mail-order service including next day delivery on many items held in stock.
01527 857500www.binocularhouse.com
sales@sherwoods-photo.com
GReen wiTcHGreen Witch is one of the UK’s leading suppliers of telescopes, binoculars and accessories for astronomy. Founded by former members of the Royal Greenwich Observatory in 1998, Green Witch is dedicated to helping you choose and use the equipment that is right for you.
We also carry an extensive range of telescopes and binoculars for nature and leisure, which you are welcome to try before you buy. Whether you visit our showrooms or buy online you can be sure of excellent service.
01924 477719 - Birstall, west yorks 01767 677025 - Gransden,
Beds & cambswww.green-witch.com
The Widescreen cenTre
02079 352580 www.widescreen-centre.co.uk
simon@widescreen-centre.co.uk
The Widescreen Centre is London’s Astronomy Showroom, located in Sherlock Holmes territory off Baker Street in the heart of Marylebone - a family owned and run business since starting out in1971. Our experienced and highly knowledgeable staff will offer you quality, choice, expertise and service - see Celestron, Sky-Watcher, Meade, Orion, Tele Vue, APM, Takahashi and much, much more besides says Simon Bennett, Widescreen’s MD and lifelong amateur astronomer, “If the correct equipment is purchased it will give a lifetime’s enjoyment. This is our mission. We will never sell you anything you don’t need” Watch out for Widescreen at Star Parties and exhibitions throughout the UK.
AsTronomiAAtronomia is the award-winning home of the biggest range of telescopes and binoculars on display in the South of England. With over 50 telescopes and even more binoculars, Astronomia brings you the widest choice from respected brands such as Celestron, Sky-Watcher, Meade, Vixen and more. Visit our store in the High Street, Dorking or check out the website. Take advantage of our full-price trade-ins on all telescopes – if you upgrade within 12 months, you don’t lose a penny!
01306 640714www.astronomia.co.uk
mail@astronomia.co.uk
ADVERTISEMENT FEATURE
Telescope House
01342 837610www.telescopehouse.com
sales@telescopehouse.com
Founded in 1785, Telescope House has been responsible for supplying many well-known Astronomers with telescopes and equipment. The late Sir Patrick Moore bought the majority of his telescopes from the company, including his very frst instrument. With a friendly showroom in Surrey, a number one ranked retail website and a service centre with fully qualifed staff, the company offers equipment from manufacturers such as Meade, Revelation, Coronado, Bresser, Skywatcher, Orion USA, TeleVue, Vixen and Explore Scientifc. Whether it’s advice on your frst telescope, to setting up advanced Astrophotography systems, the staff at Telescope House have a wealth of experience and instant access to the right stock to back it up.
TRinG AsTRonomy cenTRe
01442 822997 www.tringastro.co.uk
enquiries@tringastro.co.uk
At Tring Astronomy Centre we know that choosing the right equipment can be a minefeld, but we strongly believe that seeing telescopes in the fesh and talking to an expert in a relaxed environment can really help. That’s why we have a coffee machine, a fully stocked bicuit barrel, and 45+ telescopes on display. As well as representing leading brands such as Celestron, Sky-Watcher, Baader Planetarium, Altair Astro, Vixen, Opticron, AstroTrac, iOptron, Lunt, Starlight Instruments, ZW Optical and many more we also offer a hire service so you can even try before you buy! So what are you waiting for? Visit or contact Tring Astronomy Centre and lets talk Astronomy!
sHeRwoodsEstablished for over 60 years, we at Sherwoods are one of the Midlands leading suppliers of astronomical telescopes, binoculars and accessories. Through our website and showroom we are able to supply optics from some of the world’s leading optical manufacturers including Celestron, Skywatcher and Meade at some of the lowest prices in the UK. We offer a full mail-order service including next day delivery on many items held in stock.
01527 857500www.binocularhouse.com
sales@sherwoods-photo.com
GReen wiTcHGreen Witch is one of the UK’s leading suppliers of telescopes, binoculars and accessories for astronomy. Founded by former members of the Royal Greenwich Observatory in 1998, Green Witch is dedicated to helping you choose and use the equipment that is right for you.
We also carry an extensive range of telescopes and binoculars for nature and leisure, which you are welcome to try before you buy. Whether you visit our showrooms or buy online you can be sure of excellent service.
01924 477719 - Birstall, west yorks 01767 677025 - Gransden,
Beds & cambswww.green-witch.com
The Widescreen cenTre
02079 352580 www.widescreen-centre.co.uk
simon@widescreen-centre.co.uk
The Widescreen Centre is London’s Astronomy Showroom, located in Sherlock Holmes territory off Baker Street in the heart of Marylebone - a family owned and run business since starting out in1971. Our experienced and highly knowledgeable staff will offer you quality, choice, expertise and service - see Celestron, Sky-Watcher, Meade, Orion, Tele Vue, APM, Takahashi and much, much more besides says Simon Bennett, Widescreen’s MD and lifelong amateur astronomer, “If the correct equipment is purchased it will give a lifetime’s enjoyment. This is our mission. We will never sell you anything you don’t need” Watch out for Widescreen at Star Parties and exhibitions throughout the UK.
AsTronomiAAtronomia is the award-winning home of the biggest range of telescopes and binoculars on display in the South of England. With over 50 telescopes and even more binoculars, Astronomia brings you the widest choice from respected brands such as Celestron, Sky-Watcher, Meade, Vixen and more. Visit our store in the High Street, Dorking or check out the website. Take advantage of our full-price trade-ins on all telescopes – if you upgrade within 12 months, you don’t lose a penny!
01306 640714www.astronomia.co.uk
mail@astronomia.co.uk
skyatnightmagazine.com 2014
The guide
MA
RK G
ARL
ICK
/SC
IEN
CE
PHO
TO L
IBR
ARY
, TH
INK
STO
CK
x 3
, N
OA
O/A
UR
A/N
SF
The Local Group
Contents
With
Elizabeth Pearson
The guide
88An introduction to the Milky Way’s
neighbouring galaxies
The Milky Way is one of the mainstays in this galactic family
Brush up on your astronomy prowess with our team of expertsSkills
88
SKILLS
The Milky Way is not alone in
the Universe. Our Galaxy
and its neighbouring spiral, the
Andromeda Galaxy, are locked
together by gravity. Caught along with
them are a host of 30-50 smaller galaxies,
among them M33 in Triangulum and the
How to
90Get steadier binocular views with a pair of
stabilising techniques
Sketching
93Discover how to sketch Mars, which
reaches opposition this month
Scope doctor
95Steve Richards answers your
astro equipment queries
Magellanic Clouds. Together, they make
up the Local Group.
The term ‘Local Group’ was introduced
by Edwin Hubble in 1936 while he was
measuring the distances to extragalactic
objects. Hubble realised that several of the
objects he had catalogued were so close to
the Milky Way that they must be affected
by its gravitational pull. By that time it
was already known that most galaxies
are found in either groups or their larger
cousins, clusters, and so Hubble suggested
that these objects were all part of our
Galaxy’s own group.
The Local Group of galaxies only contains three spirals, our own
Milky Way, M31 and M33
The Milky Way
The Andromeda Galaxy, M31
The Triangulum Galaxy, M33
skyatnightmagazine.com 2014
The guide
MA
RK G
ARL
ICK
/SC
IEN
CE
PHO
TO L
IBR
ARY
, TH
INK
STO
CK
x 3
, N
OA
O/A
UR
A/N
SF
The Local Group
Contents
With
Elizabeth Pearson
The guide
88An introduction to the Milky Way’s
neighbouring galaxies
The Milky Way is one of the mainstays in this galactic family
Brush up on your astronomy prowess with our team of expertsSkills
88
SKILLS
The Milky Way is not alone in
the Universe. Our Galaxy
and its neighbouring spiral, the
Andromeda Galaxy, are locked
together by gravity. Caught along with
them are a host of 30-50 smaller galaxies,
among them M33 in Triangulum and the
How to
90Get steadier binocular views with a pair of
stabilising techniques
Sketching
93Discover how to sketch Mars, which
reaches opposition this month
Scope doctor
95Steve Richards answers your
astro equipment queries
Magellanic Clouds. Together, they make
up the Local Group.
The term ‘Local Group’ was introduced
by Edwin Hubble in 1936 while he was
measuring the distances to extragalactic
objects. Hubble realised that several of the
objects he had catalogued were so close to
the Milky Way that they must be affected
by its gravitational pull. By that time it
was already known that most galaxies
are found in either groups or their larger
cousins, clusters, and so Hubble suggested
that these objects were all part of our
Galaxy’s own group.
The Local Group of galaxies only contains three spirals, our own
Milky Way, M31 and M33
The Milky Way
The Andromeda Galaxy, M31
The Triangulum Galaxy, M33
Observing the LocaL Group
skiLLs APRIL 89
skyatnightmagazine.com 2014
Over the years astronomers have found
more nearby dwarf galaxies, upping the
number in the Local Group to several dozen.
The exact population is still a matter of
some contention: in order to be part of the
group, a galaxy needs to be gravitationally
bound to the other members, something
that can be hard to work out.
Gravitational graspMost of the galaxies in the Local Group
are satellites of either the Milky Way or the
Andromeda Galaxy. There are a few
others that are not, such as the Aquarius
and Phoenix Dwarf Galaxies, but we know
that they must be part of the group as they
are too close not to be affected by the
combined gravity of the two large spirals.
The problem comes for galaxies that are
on the edge of the group’s gravitational
infuence. Calculating distances on these
huge scales is extremely diffcult using the
usual techniques of resolving individual
stars visually and calculating redshift with
spectroscopy. In several cases a galaxy has
at frst appeared to be part of the Local
Group, only for a more precise distance
measurement to place it in a nearby group;
this happened with irregular galaxy
UGCA 86. Once proposed to be part of the
Local Group, recent studies have placed
it in the IC 342/Maffei Group, an adjacent
congregation of galaxies within 10 million
lightyears of our own.
Telling which galaxies are part of the Local
Group will be a lot easier in a few billion
years, however, as they are slowly being
pulled together. The largest two members
of the group, Andromeda and the Milky Way,
are heading towards a massive collision in
about four billion years. While this will be
the most spectacular crash these two spirals
have encountered, it won’t be the frst. The
remains of dwarf galaxies that have been
subsumed by Andromeda can be seen in
our galactic companion, while a structure
called the Virgo Stellar Stream is believed
to be what’s left of a dwarf that is currently
merging with the Milky Way. When the
largest members of the Local Group merge,
they will form a massive elliptical galaxy.
What will happen to the smaller
galaxies is a little more uncertain. Some
will get consumed in the merger, others
will continue to orbit as satellite galaxies
and some may be thrown out of the
system entirely.
Elizabeth Pearson is BBC Sky at Night Magazine’s staff writer
ThE AndroMEdA GALAXY, M31
Equipment: naked eye, binoculars, telescopeConstellation: AndromedaAt mag. +3.5, M31 is the brightest galaxy visible from the northern hemisphere; also look out for its satellite galaxies above and below it, designated M32 and M110 – you’ll need at least binoculars for these.
A few objects in the Local Group are prime targets for observing and imaging. That said, the light from these galaxies is spread out and
diffuse, meaning they can be a challenge to fnd and picking out detail is very tricky. As with most deep-sky objects, it’s critical to
observe from a very dark site – from good locations you may be able to see some of these four with the naked eye.
ThE MILKY WAY
Equipment: naked eyeThe Milky Way appears as a band of stars across the sky as we look out through the plane of our Galaxy. The exact position of the band on the sky changes throughout the year, showing us different parts of the Galaxy.
ThE LArGE And SMALL MAGELLAnIC CLoudS (LMC And SMC)
Equipment: naked eye, binoculars, telescopeConstellation: dorado/Mensa (LMC); Tucana (SMC)This duo are only visible from the southern hemisphere. The LMC is an irregular galaxy, though a strong bar-like structure near the centre suggests it may once have been a spiral; the SMC is an irregular dwarf.
ThE TrIAnGuLuM GALAXY, M33
Equipment: Binoculars, telescopeConstellation: TriangulumIn April, the mag. +5.7 Triangulum Galaxy will appear low on the horizon in the early hours of the morning. It is most easily spotted with binoculars due to its low surface brightness.
S
Observing the LocaL Group
skiLLs APRIL 89
skyatnightmagazine.com 2014
Over the years astronomers have found
more nearby dwarf galaxies, upping the
number in the Local Group to several dozen.
The exact population is still a matter of
some contention: in order to be part of the
group, a galaxy needs to be gravitationally
bound to the other members, something
that can be hard to work out.
Gravitational graspMost of the galaxies in the Local Group
are satellites of either the Milky Way or the
Andromeda Galaxy. There are a few
others that are not, such as the Aquarius
and Phoenix Dwarf Galaxies, but we know
that they must be part of the group as they
are too close not to be affected by the
combined gravity of the two large spirals.
The problem comes for galaxies that are
on the edge of the group’s gravitational
infuence. Calculating distances on these
huge scales is extremely diffcult using the
usual techniques of resolving individual
stars visually and calculating redshift with
spectroscopy. In several cases a galaxy has
at frst appeared to be part of the Local
Group, only for a more precise distance
measurement to place it in a nearby group;
this happened with irregular galaxy
UGCA 86. Once proposed to be part of the
Local Group, recent studies have placed
it in the IC 342/Maffei Group, an adjacent
congregation of galaxies within 10 million
lightyears of our own.
Telling which galaxies are part of the Local
Group will be a lot easier in a few billion
years, however, as they are slowly being
pulled together. The largest two members
of the group, Andromeda and the Milky Way,
are heading towards a massive collision in
about four billion years. While this will be
the most spectacular crash these two spirals
have encountered, it won’t be the frst. The
remains of dwarf galaxies that have been
subsumed by Andromeda can be seen in
our galactic companion, while a structure
called the Virgo Stellar Stream is believed
to be what’s left of a dwarf that is currently
merging with the Milky Way. When the
largest members of the Local Group merge,
they will form a massive elliptical galaxy.
What will happen to the smaller
galaxies is a little more uncertain. Some
will get consumed in the merger, others
will continue to orbit as satellite galaxies
and some may be thrown out of the
system entirely.
Elizabeth Pearson is BBC Sky at Night Magazine’s staff writer
ThE AndroMEdA GALAXY, M31
Equipment: naked eye, binoculars, telescopeConstellation: AndromedaAt mag. +3.5, M31 is the brightest galaxy visible from the northern hemisphere; also look out for its satellite galaxies above and below it, designated M32 and M110 – you’ll need at least binoculars for these.
A few objects in the Local Group are prime targets for observing and imaging. That said, the light from these galaxies is spread out and
diffuse, meaning they can be a challenge to fnd and picking out detail is very tricky. As with most deep-sky objects, it’s critical to
observe from a very dark site – from good locations you may be able to see some of these four with the naked eye.
ThE MILKY WAY
Equipment: naked eyeThe Milky Way appears as a band of stars across the sky as we look out through the plane of our Galaxy. The exact position of the band on the sky changes throughout the year, showing us different parts of the Galaxy.
ThE LArGE And SMALL MAGELLAnIC CLoudS (LMC And SMC)
Equipment: naked eye, binoculars, telescopeConstellation: dorado/Mensa (LMC); Tucana (SMC)This duo are only visible from the southern hemisphere. The LMC is an irregular galaxy, though a strong bar-like structure near the centre suggests it may once have been a spiral; the SMC is an irregular dwarf.
ThE TrIAnGuLuM GALAXY, M33
Equipment: Binoculars, telescopeConstellation: TriangulumIn April, the mag. +5.7 Triangulum Galaxy will appear low on the horizon in the early hours of the morning. It is most easily spotted with binoculars due to its low surface brightness.
S
90
SKILLS
The ‘grab and go’ nature of
small or medium binoculars
makes them very attractive
astronomical instruments.
Sooner or later, however, you will fnd that
you need to steady them a bit more in
order to make a critical observation.
One solution is to mount them, but a
mount immediately compromises their
portability and adds a layer of complexity.
You can, however, get steadier views
simply by changing the way you hold your
binoculars, which is what we are going
to explain this month.
Most of us instinctively hold Porro-
prism binoculars by the prism housings
and roof-prism binoculars about midway
along their length. This is tolerable for
terrestrial targets, but can quickly become
tiring when you are observing objects at
How to
Two techniques to help you split tricky double stars in no time
all
pic
tu
res: steph
en
to
nk
in
high altitudes. In order to improve things,
we need to apply some ergonomics.
Let’s assume you hold your binoculars
as described previously. When looking
through them horizontally, all the weight
is borne by your arms, which are cantilevered
out in front of you; the strain is mostly taken
by the deltoid muscles in your shoulder.
As you observe higher targets, your
forearm becomes more horizontal and
your triceps take more of the strain.
Additionally, when you observe objects at
high altitude your arms are much higher
than your heart, reducing the blood fow
to your arm muscles. This means they are
more likely to tire and start shaking. What
we need is a way of transferring the strain.
One way to do this is called the
‘triangular arm brace’, in which you
transfer some of the weight to your head
skyatnightmagazine.com 2014
Get steadier binocular viewsWith Stephen Tonkin
and neck: as you lean further back to
observe higher targets, more and more of
the weight of the binoculars rests on your
head and less is borne by your arms,
making them less liable to shake. And this
is not the only beneft.
As any structural engineer will tell you,
the triangle is the simplest and most stable
mechanical structure. By holding your
binoculars in this position, you create two
triangles with your arms – these triangles
share a common side comprised of your head
and neck. The result is an immediately
noticeable improvement in stability. This
improvement is even more marked if you
take up a position where your head is also
supported, such as lying on a sunlounger.
If the binoculars have a suffciently long
strap, we can steady the view even more by
using a second technique similar that used
Even heavy binoculars can be held steady if your arms
aren’t taking the weight
90
SKILLS
The ‘grab and go’ nature of
small or medium binoculars
makes them very attractive
astronomical instruments.
Sooner or later, however, you will fnd that
you need to steady them a bit more in
order to make a critical observation.
One solution is to mount them, but a
mount immediately compromises their
portability and adds a layer of complexity.
You can, however, get steadier views
simply by changing the way you hold your
binoculars, which is what we are going
to explain this month.
Most of us instinctively hold Porro-
prism binoculars by the prism housings
and roof-prism binoculars about midway
along their length. This is tolerable for
terrestrial targets, but can quickly become
tiring when you are observing objects at
How to
Two techniques to help you split tricky double stars in no time
all
pic
tu
res:
steph
en
to
nk
in
high altitudes. In order to improve things,
we need to apply some ergonomics.
Let’s assume you hold your binoculars
as described previously. When looking
through them horizontally, all the weight
is borne by your arms, which are cantilevered
out in front of you; the strain is mostly taken
by the deltoid muscles in your shoulder.
As you observe higher targets, your
forearm becomes more horizontal and
your triceps take more of the strain.
Additionally, when you observe objects at
high altitude your arms are much higher
than your heart, reducing the blood fow
to your arm muscles. This means they are
more likely to tire and start shaking. What
we need is a way of transferring the strain.
One way to do this is called the
‘triangular arm brace’, in which you
transfer some of the weight to your head
skyatnightmagazine.com 2014
Get steadier binocular viewsWith Stephen Tonkin
and neck: as you lean further back to
observe higher targets, more and more of
the weight of the binoculars rests on your
head and less is borne by your arms,
making them less liable to shake. And this
is not the only beneft.
As any structural engineer will tell you,
the triangle is the simplest and most stable
mechanical structure. By holding your
binoculars in this position, you create two
triangles with your arms – these triangles
share a common side comprised of your head
and neck. The result is an immediately
noticeable improvement in stability. This
improvement is even more marked if you
take up a position where your head is also
supported, such as lying on a sunlounger.
If the binoculars have a suffciently long
strap, we can steady the view even more by
using a second technique similar that used
Even heavy binoculars can be held steady if your arms
aren’t taking the weight
SKILLS april 91
STEP 1To fnd the correct position for your hands, cup them and hold them to your face so that the top knuckle of your thumb rests securely in the indent of your eye socket; the lower bone of your thumb should rest comfortably on your cheekbone.
STEP 2With the same cupped-hand position, hold the prism housings of the binoculars with your third and fourth fngers. Your forefnger will rest lightly on the eyepiece barrel and your middle fnger on the eyepiece bridge. Your palms will take the weight of the binoculars.
STEP 3Raise the binoculars to your eyes and re-settle your thumbs into their original positions resting on your cheekbones. If you have centre-focus binoculars, use your middle or ring fnger to adjust the focus wheel. If you have individual eyepiece focusing, use your forefngers.
STEP 4For the ultra-stable rife sling hold, you may need a longer strap. Cut a 1.7m length of nylon webbing and attach it to the strap lugs of your binoculars. Secure the strap with the 3-bar buckles, with the free ends trapped against the buckles.
STEP 5Hold the binoculars in front of you so the strap is looped down and, one at a time, put your arms through the strap and adjust its position so that it comes to just above your elbows. Hold the binoculars the same way as you did before.
STEP 6Raise the binoculars to your eyes as before and tension the strap by pushing your elbows apart. You should feel the binoculars pushing down on your hands and the whole ‘system’ of arms, head and straps becoming very rigid.
skyatnightmagazine.com 2014
by marksmen to steady a rife. For this
reason, we call it the ‘rife sling’ method.
It works by creating tension between your
arms and the binoculars; the tension reduces
the ability of the binoculars to shake.
Armed and ready?This technique can be slightly awkward
until you get used to it, but get it right
and it is quite comfortable. The rife sling
method doesn’t quite have the stability of
mounted binoculars, but it’s not a long way
off for a pair of 10x50s. You should certainly
fnd that double stars that used to be tricky
to split suddenly seem much easier.
Even on larger binoculars that shouldn’t
really be hand-held – 15x70s for example
– the difference between the rife sling
approach and the normal way of holding
them is quite marked. Not only will you
fnd that more detail becomes visible in
large ‘fuzzy blobs’ like the Orion Nebula
and the Andromeda Galaxy, but also some
clusters will resolve more easily and seem
to have more stars. It can also help
distinguish between stars and those very
small objects that look stellar at low
magnifcation, such as active galaxy M77
in Cetus or the Ring Nebula, M57, in Lyra.
An added bonus to the improved
stability is that holding your binoculars
like this also has the advantage of
considerably reducing arm fatigue, so your
binocular observing sessions can become
longer and much more productive.
Stephen Tonkin writes our Binocular tour each month – fnd it in the Sky Guide
S
STEP-BY-STEP GUIDETOOLS AND
MATERIALSif you need a new strap for the ‘rife sling’ method
Finish
use a soldering iron to heat seal cut ends to prevent them fraying.
Materials
approximately 1.7m of nylon webbing to suit the strap-lugs on your binoculars, which are usually about 8mm wide, and a pair of 3-bar slide buckles to ft the webbing; you may be able to reuse the ones on your existing strap.
tools
scissors, craft knife or hot cutter, tape measure, ruler.
SKILLS april 91
STEP 1To fnd the correct position for your hands, cup them and hold them to your face so that the top knuckle of your thumb rests securely in the indent of your eye socket; the lower bone of your thumb should rest comfortably on your cheekbone.
STEP 2With the same cupped-hand position, hold the prism housings of the binoculars with your third and fourth fngers. Your forefnger will rest lightly on the eyepiece barrel and your middle fnger on the eyepiece bridge. Your palms will take the weight of the binoculars.
STEP 3Raise the binoculars to your eyes and re-settle your thumbs into their original positions resting on your cheekbones. If you have centre-focus binoculars, use your middle or ring fnger to adjust the focus wheel. If you have individual eyepiece focusing, use your forefngers.
STEP 4For the ultra-stable rife sling hold, you may need a longer strap. Cut a 1.7m length of nylon webbing and attach it to the strap lugs of your binoculars. Secure the strap with the 3-bar buckles, with the free ends trapped against the buckles.
STEP 5Hold the binoculars in front of you so the strap is looped down and, one at a time, put your arms through the strap and adjust its position so that it comes to just above your elbows. Hold the binoculars the same way as you did before.
STEP 6Raise the binoculars to your eyes as before and tension the strap by pushing your elbows apart. You should feel the binoculars pushing down on your hands and the whole ‘system’ of arms, head and straps becoming very rigid.
skyatnightmagazine.com 2014
by marksmen to steady a rife. For this
reason, we call it the ‘rife sling’ method.
It works by creating tension between your
arms and the binoculars; the tension reduces
the ability of the binoculars to shake.
Armed and ready?This technique can be slightly awkward
until you get used to it, but get it right
and it is quite comfortable. The rife sling
method doesn’t quite have the stability of
mounted binoculars, but it’s not a long way
off for a pair of 10x50s. You should certainly
fnd that double stars that used to be tricky
to split suddenly seem much easier.
Even on larger binoculars that shouldn’t
really be hand-held – 15x70s for example
– the difference between the rife sling
approach and the normal way of holding
them is quite marked. Not only will you
fnd that more detail becomes visible in
large ‘fuzzy blobs’ like the Orion Nebula
and the Andromeda Galaxy, but also some
clusters will resolve more easily and seem
to have more stars. It can also help
distinguish between stars and those very
small objects that look stellar at low
magnifcation, such as active galaxy M77
in Cetus or the Ring Nebula, M57, in Lyra.
An added bonus to the improved
stability is that holding your binoculars
like this also has the advantage of
considerably reducing arm fatigue, so your
binocular observing sessions can become
longer and much more productive.
Stephen Tonkin writes our Binocular tour each month – fnd it in the Sky Guide
S
STEP-BY-STEP GUIDETOOLS AND
MATERIALSif you need a new strap for the ‘rife sling’ method
Finish
use a soldering iron to heat seal cut ends to prevent them fraying.
Materials
approximately 1.7m of nylon webbing to suit the strap-lugs on your binoculars, which are usually about 8mm wide, and a pair of 3-bar slide buckles to ft the webbing; you may be able to reuse the ones on your existing strap.
tools
scissors, craft knife or hot cutter, tape measure, ruler.
The Great Courses®, Unit A, Sovereign Business Park,
Brenda Road, Hartlepool, TS25 1NN. Terms and conditions
apply. See www.thegreatcourses.co.uk for details.
For 24 years, The Great Courses has brought the
world’s foremost educators to millions who want to
go deeper into the subjects that matter most. No
exams. No homework. Just a world of knowledge
available anytime, anywhere. Download or stream
to your laptop or PC, or use our free mobile apps
for iPad, iPhone, or Android. Nearly 500 courses
available at www.thegreatcourses.co.uk.
LIM
ITED TIME OFFE
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RDER BY 18 M
AY
Black Holes ExplainedTaught by Professor Alex FilippenkoUNIVERSITY OF CALIFORNIA, BERKELEY
LECTURE TITLES
1. A General Introduction to Black Holes
2. The Violent Deaths of Massive Stars
3. Gamma-Ray Bursts—The Birth of Black Holes
4. Searching for Stellar-Mass Black Holes
5. Monster of the Milky Way and Other Galaxies
6. Quasars—Feasting Supermassive Black Holes
7. Gravitational Waves—Ripples in Space-Time
8. The Wildest Ride in the Universe
9. Shortcuts through the Universe and Beyond?
10. Stephen Hawking and Black Hole Evaporation
11. Black Holes and the Holographic Universe
12. Black Holes and the Large Hadron Collider
Black Holes ExplainedCourse no. 1841 | 12 lectures (30 minutes/lecture)
SAVE £18
DVD £29.99 NOW £11.99+£2.99 Postage and Packing
Priority Code: 96520
Make Sense of Black HolesBlack holes. They are one of the most exotic, mind-boggling, and profound subjects in astrophysics. Not only are they at the heart of some of the most intriguing phenomena in the cosmos, they’re the gateway to fundamental and cutting-edge concepts like general relativity and wormholes.
Nearly everyone has heard of black holes, but few people outside of complex scientific fields understand their true nature and their implications for our universe. Black Holes Explained finally makes this awe-inspiring cosmological subject accessible, with 12 lavishly illustrated lectures delivered by distinguished astronomer and award-winning professor Alex Filippenko. As he presents the actual science behind these amazing objects, you’ll make sense of Einstein rings, photon spheres, event horizons, and other concepts central to the study of black holes. Like its subject matter, this course is intriguing, eye-opening, and essential to your knowledge of how the universe works.
Of er expires 18/05/14
0800 298 9796WWW.THEGREATCOURSES.CO.UK/3SAN
The Great Courses®, Unit A, Sovereign Business Park,
Brenda Road, Hartlepool, TS25 1NN. Terms and conditions
apply. See www.thegreatcourses.co.uk for details.
For 24 years, The Great Courses has brought the
world’s foremost educators to millions who want to
go deeper into the subjects that matter most. No
exams. No homework. Just a world of knowledge
available anytime, anywhere. Download or stream
to your laptop or PC, or use our free mobile apps
for iPad, iPhone, or Android. Nearly 500 courses
available at www.thegreatcourses.co.uk.
LIM
ITED TIME OFFE
R
55%off
O
RDER BY 18 M
AY
Black Holes ExplainedTaught by Professor Alex FilippenkoUNIVERSITY OF CALIFORNIA, BERKELEY
LECTURE TITLES
1. A General Introduction to Black Holes
2. The Violent Deaths of Massive Stars
3. Gamma-Ray Bursts—The Birth of Black Holes
4. Searching for Stellar-Mass Black Holes
5. Monster of the Milky Way and Other Galaxies
6. Quasars—Feasting Supermassive Black Holes
7. Gravitational Waves—Ripples in Space-Time
8. The Wildest Ride in the Universe
9. Shortcuts through the Universe and Beyond?
10. Stephen Hawking and Black Hole Evaporation
11. Black Holes and the Holographic Universe
12. Black Holes and the Large Hadron Collider
Black Holes ExplainedCourse no. 1841 | 12 lectures (30 minutes/lecture)
SAVE £18
DVD £29.99 NOW £11.99+£2.99 Postage and Packing
Priority Code: 96520
Make Sense of Black HolesBlack holes. They are one of the most exotic, mind-boggling, and profound subjects in astrophysics. Not only are they at the heart of some of the most intriguing phenomena in the cosmos, they’re the gateway to fundamental and cutting-edge concepts like general relativity and wormholes.
Nearly everyone has heard of black holes, but few people outside of complex scientific fields understand their true nature and their implications for our universe. Black Holes Explained finally makes this awe-inspiring cosmological subject accessible, with 12 lavishly illustrated lectures delivered by distinguished astronomer and award-winning professor Alex Filippenko. As he presents the actual science behind these amazing objects, you’ll make sense of Einstein rings, photon spheres, event horizons, and other concepts central to the study of black holes. Like its subject matter, this course is intriguing, eye-opening, and essential to your knowledge of how the universe works.
Of er expires 18/05/14
0800 298 9796WWW.THEGREATCOURSES.CO.UK/3SAN
SKILLS APRIL 93
Sketching
all
pic
tu
res: c
aro
l la
ko
mia
k
skyatnightmagazine.com 2014
MarsWith Carol Lakomiak
Like all of the naked-eye
planets in our Solar System,
Mars has been known to
mankind since ancient times
– Egyptian astronomers knew of its
retrograde motion by 1534 BC. When
Galileo viewed it through his telescope
over 3,000 years later, we fnally had a
closer look at Mars and we’ve been
studying it ever since.
This month, Mars’s opposition
occurs at 20:57 UT on the 8th; the planet
makes its closest approach to Earth, at a
distance of 92,386,484km, on the 14th at
12:54 UT. Mars’s size and magnitude will
fuctuate during the month, but not
enough to affect your choice of sketching
dates. Different features will come into
view though, so what you see might not
be the same as what’s shown here.
Mars is shown here the way it appears
to the naked-eye at culmination: north is
up and surface features rotate from left to
right (from the following limb towards
the preceding limb). Different telescopes
present different views though, so be sure
to mark your sketch with ‘N’ or ‘S’ for
north or south and ‘F’ or ‘P’ for following
or preceding). Following and preceding
are used instead of east and west to avoid
confusion, because when Mars is viewed
from the UK, its eastern limb faces
towards the western horizon.
Colour flters are useful for viewing
Mars. Casual observers often use a few of
them to increase contrast and enhance
clouds or dust storms. Advanced Mars
observers use a wider variety of flters to
help them detect details of the features
they’re studying. If you don’t have any
flters, don’t worry – just take your time
and sketch what you see.
Usually we include everything in the
eyepiece’s view when sketching, but use
your entire circle to represent Mars – this
way, you’ll be able to ft in all the details
you see. If you want your sketch to look
more like what you see in the eyepiece,
blacken the background sky. Do this with
a 9B pencil, black permanent marker or a
photo-editing program.
Carol Lakomiak is BBC Sky at Night Magazine’s sketching expert
Step 1
Make a swatch of B graphite on a small piece of paper. Then use your fngertip to evenly smudge the graphite over your entire sketching circle. Next, use the ‘fat’ side of the pencil’s graphite to lightly and evenly shade any dark features you see.
Name: Mars
type of object: Planet
coNSteLLatIoN: Virgo
Ra: 13h 22m to 12h 43m
dec: –05° 51’ to –02° 57’
equIpmeNt:
6-inch refector (or larger); B pencil; blending stump; soft and hard art erasers
beSt tIme to SKetch:
1-30 April, 11pm-2am BST (10pm-1am UT)
fIeLd of VIew ShowN:
15 arcminutes; 400x magnifcation
Step 2
Soften the dark features with a blending stump (small, circular motions work best). To complete the shading process, you’ll need to darken some areas. Do this by rubbing the blending stump on the graphite swatch, and using it like a pencil to bring out the darker areas.
Step 3
Indicate Mars’s bright areas by removing the background shading. For bright areas with a diffuse edge, round the tip of a soft eraser and ‘dab’ the graphite away. For bright areas with a distinct edge, cut the end of a hard eraser so it is fat and use it to ‘carve’ the graphite away.
Need TO KNOW
SKILLS
North polar cap
N
P
Mare Acidalium
Arabia
Eden
Sinus Meridiani Sinus
Sabaeus
Syrtis Major
Hellas
AeriaMoab
Utopia
Mare Tyrrhenum
Iapygia Viridis
N
P
N
P
SKILLS APRIL 93
Sketching
all
pic
tu
res:
ca
ro
l la
ko
mia
k
skyatnightmagazine.com 2014
MarsWith Carol Lakomiak
Like all of the naked-eye
planets in our Solar System,
Mars has been known to
mankind since ancient times
– Egyptian astronomers knew of its
retrograde motion by 1534 BC. When
Galileo viewed it through his telescope
over 3,000 years later, we fnally had a
closer look at Mars and we’ve been
studying it ever since.
This month, Mars’s opposition
occurs at 20:57 UT on the 8th; the planet
makes its closest approach to Earth, at a
distance of 92,386,484km, on the 14th at
12:54 UT. Mars’s size and magnitude will
fuctuate during the month, but not
enough to affect your choice of sketching
dates. Different features will come into
view though, so what you see might not
be the same as what’s shown here.
Mars is shown here the way it appears
to the naked-eye at culmination: north is
up and surface features rotate from left to
right (from the following limb towards
the preceding limb). Different telescopes
present different views though, so be sure
to mark your sketch with ‘N’ or ‘S’ for
north or south and ‘F’ or ‘P’ for following
or preceding). Following and preceding
are used instead of east and west to avoid
confusion, because when Mars is viewed
from the UK, its eastern limb faces
towards the western horizon.
Colour flters are useful for viewing
Mars. Casual observers often use a few of
them to increase contrast and enhance
clouds or dust storms. Advanced Mars
observers use a wider variety of flters to
help them detect details of the features
they’re studying. If you don’t have any
flters, don’t worry – just take your time
and sketch what you see.
Usually we include everything in the
eyepiece’s view when sketching, but use
your entire circle to represent Mars – this
way, you’ll be able to ft in all the details
you see. If you want your sketch to look
more like what you see in the eyepiece,
blacken the background sky. Do this with
a 9B pencil, black permanent marker or a
photo-editing program.
Carol Lakomiak is BBC Sky at Night Magazine’s sketching expert
Step 1
Make a swatch of B graphite on a small piece of paper. Then use your fngertip to evenly smudge the graphite over your entire sketching circle. Next, use the ‘fat’ side of the pencil’s graphite to lightly and evenly shade any dark features you see.
Name: Mars
type of object: Planet
coNSteLLatIoN: Virgo
Ra: 13h 22m to 12h 43m
dec: –05° 51’ to –02° 57’
equIpmeNt:
6-inch refector (or larger); B pencil; blending stump; soft and hard art erasers
beSt tIme to SKetch:
1-30 April, 11pm-2am BST (10pm-1am UT)
fIeLd of VIew ShowN:
15 arcminutes; 400x magnifcation
Step 2
Soften the dark features with a blending stump (small, circular motions work best). To complete the shading process, you’ll need to darken some areas. Do this by rubbing the blending stump on the graphite swatch, and using it like a pencil to bring out the darker areas.
Step 3
Indicate Mars’s bright areas by removing the background shading. For bright areas with a diffuse edge, round the tip of a soft eraser and ‘dab’ the graphite away. For bright areas with a distinct edge, cut the end of a hard eraser so it is fat and use it to ‘carve’ the graphite away.
Need TO KNOW
SKILLS
North polar cap
N
P
Mare Acidalium
Arabia
Eden
Sinus Meridiani Sinus
Sabaeus
Syrtis Major
Hellas
AeriaMoab
Utopia
Mare Tyrrhenum
Iapygia Viridis
N
P
N
P
LOW PRICES we’ll match any genuine web price!
Visionary Classic 10x50Good value and excellent value for money.
Kepler GL 10x50A strong and sturdy binocular - excellent value for money and a
great tool for viewing the night sky at a great price.
£29.99
£34.99
Visionary HDVery high quality optics at a great price. Traditional styled binoculars featuring BAK4 prisms, fully coated lenses, Long eye relief, rubber armour body.
HD 8x42 ......£69.99HD 8x56 ......£99.99HD 7x50 ......£79.99HD 10x50 ....£79.99
HUGE RANGE of eyepieces and accessories
102 EDtelescope outftwith 2” SWA eyepice,
2” 90M and 8.5x50 illuminated fnder
£799.00
Eyepieces & AccessoriesEYEPIECES/ACCESSORIES
Plossl 5mm (1.25”) ................................................................. £14.99 Plossl 10mm (1.25”) .............................................................. £14.99 Plossl 15mm (1.25”) .............................................................. £14.99 Plossl 20mm (1.25”) .............................................................. £14.99 Plossl 25mm (1.25”) .............................................................. £17.99 Plossl 30mm (1.25”) .............................................................. £17.99 Plossl 40mm (1.25”) ............................................................. £19.99 Super Wide angle 10mm (1.25”) ....................................... £39.99 Super Wide angle 20mm (1.25”) ....................................... £44.99 FF 8mm (1.25”) ....................................................................... £49.99 FF 12mm (1.25”) .................................................................... £49.99 FF 19mm (1.25”) .................................................................... £49.99 FF 27mm (1.25”) .................................................................... £49.99 SWA 26mm (2”) ..................................................................... £79.99 SWA 32mm (2”) ..................................................................... £79.99 SWA 38mm (2”) ..................................................................... £79.99 SWA82 8.8mm (1.25”) ...................................................... £129.99 SWA82 14mm (1.25”) ....................................................... £149.99 SWA82 24mm (2”) ............................................................. £199.99
HD 12x60 ....£89.99HD 15x70 ....£99.99HD 20x80 .£149.99HD 20x80T .£249.99
Olivon QB 10x50Excellent quality traditional styled binoculars. Rubber armoured, water resistant and BAK 4 optics.
Ostara Elinor 10x50BAK 4 prisms, Fully multi coated , waterproof and nitrogen flled.
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£179.99
Ostara Prophecy 10x50The ultimate in high quality viewing. Highest quality, full multicoated optics, prism and phase coatings for superb brightness, clarity and contrast. Waterproof and nitrogenflled, Fully checked and tested in the UK.
£299.99
Stockists of
Visionary Saxon
Visionary HD 15x70 only £ 99.99
Visionary
FIRST VIEW3” starter telescope complete with fnderscope, table base and eyepieces.
£49.99
Clearview Binoculars: Four Square Chapel, Mapplewell. S75 6GG. Tel 01226 383736.
www.clearviewbinoculars.co.uk Callers very welcome, please check website for opening times.
Binocular Outlet. Check our website or visit us at our shows throughout the UK.
www.binocularoutlet.co.uk
The Far-Sighted binocular company is a group of independent specialist optical goods suppliers. For more information please visit www.far-sighted.co.uk.
Offers are subject to availability and at participating outlets only. Prices and specifcations are subject to change without notice.
LOW PRICES we’ll match any genuine web price!
Visionary Classic 10x50Good value and excellent value for money.
Kepler GL 10x50A strong and sturdy binocular - excellent value for money and a
great tool for viewing the night sky at a great price.
£29.99
£34.99
Visionary HDVery high quality optics at a great price. Traditional styled binoculars featuring BAK4 prisms, fully coated lenses, Long eye relief, rubber armour body.
HD 8x42 ......£69.99HD 8x56 ......£99.99HD 7x50 ......£79.99HD 10x50 ....£79.99
HUGE RANGE of eyepieces and accessories
102 EDtelescope outftwith 2” SWA eyepice,
2” 90M and 8.5x50 illuminated fnder
£799.00
Eyepieces & AccessoriesEYEPIECES/ACCESSORIES
Plossl 5mm (1.25”) ................................................................. £14.99 Plossl 10mm (1.25”) .............................................................. £14.99 Plossl 15mm (1.25”) .............................................................. £14.99 Plossl 20mm (1.25”) .............................................................. £14.99 Plossl 25mm (1.25”) .............................................................. £17.99 Plossl 30mm (1.25”) .............................................................. £17.99 Plossl 40mm (1.25”) ............................................................. £19.99 Super Wide angle 10mm (1.25”) ....................................... £39.99 Super Wide angle 20mm (1.25”) ....................................... £44.99 FF 8mm (1.25”) ....................................................................... £49.99 FF 12mm (1.25”) .................................................................... £49.99 FF 19mm (1.25”) .................................................................... £49.99 FF 27mm (1.25”) .................................................................... £49.99 SWA 26mm (2”) ..................................................................... £79.99 SWA 32mm (2”) ..................................................................... £79.99 SWA 38mm (2”) ..................................................................... £79.99 SWA82 8.8mm (1.25”) ...................................................... £129.99 SWA82 14mm (1.25”) ....................................................... £149.99 SWA82 24mm (2”) ............................................................. £199.99
HD 12x60 ....£89.99HD 15x70 ....£99.99HD 20x80 .£149.99HD 20x80T .£249.99
Olivon QB 10x50Excellent quality traditional styled binoculars. Rubber armoured, water resistant and BAK 4 optics.
Ostara Elinor 10x50BAK 4 prisms, Fully multi coated , waterproof and nitrogen flled.
£84.99
£179.99
Ostara Prophecy 10x50The ultimate in high quality viewing. Highest quality, full multicoated optics, prism and phase coatings for superb brightness, clarity and contrast. Waterproof and nitrogenflled, Fully checked and tested in the UK.
£299.99
Stockists of
Visionary Saxon
Visionary HD 15x70 only £ 99.99
Visionary
FIRST VIEW3” starter telescope complete with fnderscope, table base and eyepieces.
£49.99
Clearview Binoculars: Four Square Chapel, Mapplewell. S75 6GG. Tel 01226 383736.
www.clearviewbinoculars.co.uk Callers very welcome, please check website for opening times.
Binocular Outlet. Check our website or visit us at our shows throughout the UK.
www.binocularoutlet.co.uk
The Far-Sighted binocular company is a group of independent specialist optical goods suppliers. For more information please visit www.far-sighted.co.uk.
Offers are subject to availability and at participating outlets only. Prices and specifcations are subject to change without notice.
skills APRIL 95
skyatnightmagazine.com 2014
Our resident equipment specialist cures your optical ailments and technical maladies
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ksu
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ca
sseg
ra
in il
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y pa
ul
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ott
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, pa
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wh
itfi
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Email your queries to scopedoctor@skyatnightmagazine.com
Maksutov-Cassegrain telescopes are
designed to give a long focal length
within a short optical tube by using a
folded light path. The design requires
a meniscus correcting lens at the front
of the instrument. These can be quite
thick and heavy, so tend to limit the
maximum aperture size of amateur
instruments to less than 8 inches.
Typical focal ratios are in the region
of f/12 to f/15, so a typical 5-inch
telescope would have a focal length
of around 1,500mm, while an
8-inch version would have a focal
length around 2,700mm. Focal
lengths of this size give quite high
magnifcation with a given eyepiece
making Maksutov-Cassegrains
most suitable for Solar System
observing. However, they can also
Which eyepieces are suitable for Maksutov-Cassegrains and how can I ensure the widest feld of view? DaviD Frampton
be used to observe globular clusters
and many galaxies but the high
magnifcation Maksutov-Cassegrains
are capable of can result in quite a
narrow feld of view.
Some of the latest Maksutov-
Cassegrain telescopes can physically
take wide-feld 2-inch eyepieces. But
it’s worth bearing in mind that if the
telescope’s rear aperture is narrower
than the eyepiece’s feld stop, you
may not achieve a fully illuminated
feld of view.
Ideal eyepieces would be either the
1.25-inch 24mm Tele Vue Panoptic
or the Baader Hyperion 24mm, both
of which have a 68° apparent feld of
view. The use of a focal reducer with
this design is not recommended.
Will the Orion Mini-Guider be enough to guide my Celestron VX8 or do I need something bigger? Keith moore
Finder-guiders like the Orion
Mini-Guider, Altair Astro 60mm
Miniguider or Altair Astro
Finderscope (pictured right)
that have been modifed
with special adaptor rings
are becoming very popular
for autoguiding mounts
when imaging deep-sky objects.
Their lightness and compact
dimensions, combined with close coupling
to the imaging telescope, which reduces the risk of
fexure, makes them a compelling purchase. The
wide feld of view afforded by these diminutive
guide telescopes also makes the task of locating
suitable guide stars easy.
With the sub-pixel guiding accuracy provided
by modern autoguiding software, even the short
focal lengths of these mini-guiders can be used
to guide imaging telescopes with focal lengths
of over 1,200mm.
The Celestron VX8 is available as either an 8-inch
Newtonian Refector with a focal length of
1,000mm or an 8-inch Schmidt-Cassegrain with a
focal length of 2,032mm. These mini-guiders would
be suitable for the Newtonian but for the Schmidt-
Cassegrain, an 80mm refractor or off-axis guider
would be required for guiding.
Steve richards is a keen astro imager and an astronomy equipment expert
SKILLS
With Steve Richards
ScopedOctOr
Þ Maksutov-Cassegrains fold the light path to increase the scope’s focal length
StEVE’S TOP TIPWhat’s the best way to store my telescope for
long periods of time?
careful long-term storage of a telescope is
important to ensure that it remains in good
condition and ready for use. dust and moisture
are the greatest concerns, so you should choose
somewhere that is dry, well-ventilated but not
too warm and then take precautions to keep
dust at bay. ensure that the focuser tube is fully
retracted and ftted with a dust cap and that
the front of the telescope is also ftted with a
dust cap. if you don’t have the original cap,
a shower hat can often be used instead.
Primary mirrorStarlight
Starlight
Meniscus lens
Coated spot
Eyepiece
skills APRIL 95
skyatnightmagazine.com 2014
Our resident equipment specialist cures your optical ailments and technical maladies
ma
ksu
tov
ca
sseg
ra
in il
lust
ra
tio
n b
y pa
ul
wo
ott
on
, pa
ul
wh
itfi
eld
Email your queries to scopedoctor@skyatnightmagazine.com
Maksutov-Cassegrain telescopes are
designed to give a long focal length
within a short optical tube by using a
folded light path. The design requires
a meniscus correcting lens at the front
of the instrument. These can be quite
thick and heavy, so tend to limit the
maximum aperture size of amateur
instruments to less than 8 inches.
Typical focal ratios are in the region
of f/12 to f/15, so a typical 5-inch
telescope would have a focal length
of around 1,500mm, while an
8-inch version would have a focal
length around 2,700mm. Focal
lengths of this size give quite high
magnifcation with a given eyepiece
making Maksutov-Cassegrains
most suitable for Solar System
observing. However, they can also
Which eyepieces are suitable for Maksutov-Cassegrains and how can I ensure the widest feld of view? DaviD Frampton
be used to observe globular clusters
and many galaxies but the high
magnifcation Maksutov-Cassegrains
are capable of can result in quite a
narrow feld of view.
Some of the latest Maksutov-
Cassegrain telescopes can physically
take wide-feld 2-inch eyepieces. But
it’s worth bearing in mind that if the
telescope’s rear aperture is narrower
than the eyepiece’s feld stop, you
may not achieve a fully illuminated
feld of view.
Ideal eyepieces would be either the
1.25-inch 24mm Tele Vue Panoptic
or the Baader Hyperion 24mm, both
of which have a 68° apparent feld of
view. The use of a focal reducer with
this design is not recommended.
Will the Orion Mini-Guider be enough to guide my Celestron VX8 or do I need something bigger? Keith moore
Finder-guiders like the Orion
Mini-Guider, Altair Astro 60mm
Miniguider or Altair Astro
Finderscope (pictured right)
that have been modifed
with special adaptor rings
are becoming very popular
for autoguiding mounts
when imaging deep-sky objects.
Their lightness and compact
dimensions, combined with close coupling
to the imaging telescope, which reduces the risk of
fexure, makes them a compelling purchase. The
wide feld of view afforded by these diminutive
guide telescopes also makes the task of locating
suitable guide stars easy.
With the sub-pixel guiding accuracy provided
by modern autoguiding software, even the short
focal lengths of these mini-guiders can be used
to guide imaging telescopes with focal lengths
of over 1,200mm.
The Celestron VX8 is available as either an 8-inch
Newtonian Refector with a focal length of
1,000mm or an 8-inch Schmidt-Cassegrain with a
focal length of 2,032mm. These mini-guiders would
be suitable for the Newtonian but for the Schmidt-
Cassegrain, an 80mm refractor or off-axis guider
would be required for guiding.
Steve richards is a keen astro imager and an astronomy equipment expert
SKILLS
With Steve Richards
ScopedOctOr
Þ Maksutov-Cassegrains fold the light path to increase the scope’s focal length
StEVE’S TOP TIPWhat’s the best way to store my telescope for
long periods of time?
careful long-term storage of a telescope is
important to ensure that it remains in good
condition and ready for use. dust and moisture
are the greatest concerns, so you should choose
somewhere that is dry, well-ventilated but not
too warm and then take precautions to keep
dust at bay. ensure that the focuser tube is fully
retracted and ftted with a dust cap and that
the front of the telescope is also ftted with a
dust cap. if you don’t have the original cap,
a shower hat can often be used instead.
Primary mirrorStarlight
Starlight
Meniscus lens
Coated spot
Eyepiece
High ReflectivityCoating
www.orionoptics.co.uk
Increase the efficiency of yourreflector by up to 25%
tech enquiries: john@orionoptics.co.uk
Telephone 01782 614200
Our HI-LUX coating can be applied to almost anyreflector, in virtually any condition or no matter howold. Improves the reflective efficiency of your mirrors.
Find out more onour website: Optics >Mirror Recoatingor call / email
Galloway astronomy Centre
Prices from £26 pppn
Contact Mike Alexander: Craiglemine Cottage, Glasserton,
Dumfries & Galloway DG8 8NE • 01988 500594
enquiries@gallowayastro.com • www.gallowayastro.com
We provide all you need with:
• Telescopes up to 400mm aperture
• Free help and guidance
• Beginner Astronomy Courses
• B&B accommodation and evening meals
• Skywatcher and Celestron Telescope Dealer
near the UK’s 1st Dark sky Park If you are inspired to learn more about the night sky, book your stay for a
great experience under the UK’s darkest skies. Now in business for 10 years.
High quality spectroscopic gratings designed specifcally for ease of use
with webcams, video and CCD imagers.
These simple devices make a perfect introduction to the fascinating world
of spectroscopy, revealing the hidden information contained in the light from
stars and other objects.
add a new dimension to your imaging
With thestar analyser
Used like standard 1.25” flters
Choice of 2 models, starting from
£95.30
See our website for more information
www.patonhawksley.co.uk
NortherN optics A s t r o A c c e s s o r i e s i n L i n c o l n s h i r e
Visit us (Weekends)
Waters Edge Visitors Centre Maltkiln Road, Barton Upon Humber
North Lincolnshire DN18 5JR
07779 122 121 (Weekends)
01724 782022 (Mon-Fri)
Open 10.00am-3.30pm (Sat & Sun)
www.northernoptics.co.uk
25
yE
AR
S
e x p e r i e n c e
Stockist ofEyepieces, flters, barlows,
camera adapters, binoculars
and much more
check
website
for latest
ofers
High ReflectivityCoating
www.orionoptics.co.uk
Increase the efficiency of yourreflector by up to 25%
tech enquiries: john@orionoptics.co.uk
Telephone 01782 614200
Our HI-LUX coating can be applied to almost anyreflector, in virtually any condition or no matter howold. Improves the reflective efficiency of your mirrors.
Find out more onour website: Optics >Mirror Recoatingor call / email
Galloway astronomy Centre
Prices from £26 pppn
Contact Mike Alexander: Craiglemine Cottage, Glasserton,
Dumfries & Galloway DG8 8NE • 01988 500594
enquiries@gallowayastro.com • www.gallowayastro.com
We provide all you need with:
• Telescopes up to 400mm aperture
• Free help and guidance
• Beginner Astronomy Courses
• B&B accommodation and evening meals
• Skywatcher and Celestron Telescope Dealer
near the UK’s 1st Dark sky Park If you are inspired to learn more about the night sky, book your stay for a
great experience under the UK’s darkest skies. Now in business for 10 years.
High quality spectroscopic gratings designed specifcally for ease of use
with webcams, video and CCD imagers.
These simple devices make a perfect introduction to the fascinating world
of spectroscopy, revealing the hidden information contained in the light from
stars and other objects.
add a new dimension to your imaging
With thestar analyser
Used like standard 1.25” flters
Choice of 2 models, starting from
£95.30
See our website for more information
www.patonhawksley.co.uk
NortherN optics A s t r o A c c e s s o r i e s i n L i n c o l n s h i r e
Visit us (Weekends)
Waters Edge Visitors Centre Maltkiln Road, Barton Upon Humber
North Lincolnshire DN18 5JR
07779 122 121 (Weekends)
01724 782022 (Mon-Fri)
Open 10.00am-3.30pm (Sat & Sun)
www.northernoptics.co.uk
25
yE
AR
S
e x p e r i e n c e
Stockist ofEyepieces, flters, barlows,
camera adapters, binoculars
and much more
check
website
for latest
ofers
HOW WE RATE
Each category is given a mark out of fve stars according to how well it performs. The ratings are:
★★★★★ Outstanding ★★★★★ Very good ★★★★★ Good★★★★★ Average ★★★★★ Poor/Avoid
REVIEWS APRIL 97
skyatnightmagazine.com 2014
Bringing you the best in equipment and accessories each month, as reviewed by our team of astro experts
Find out how the huge Meade
LX600 improves on its forebears
98
Reviews
This month’s reviews
First light
98Meade LX600-ACF
12-inch Schmidt-Cassegrain
102William Optics
GTF 102 fve-element astrograph
Books
110We rate
four of the latest astronomy titles
Gear
112 Including this
Baader Classic Q-Eyepiece Set
106QSI 683 WSG-8
CCD camera with in-built flter wheel
SEE INTERACTIVE 360° MODELS OF ALL OUR FIRST LIGHT REVIEWS AT WWW.SKYATNIGHTMAGAZINE.COM
Tried & tested
WW
W.T
hES
ECrE
TSTu
DIO
.nET
X 4
Find out more about how we review equipment at: www.skyatnightmagazine.com/scoring-categories
HOW WE RATE
Each category is given a mark out of fve stars according to how well it performs. The ratings are:
★★★★★ Outstanding ★★★★★ Very good ★★★★★ Good★★★★★ Average ★★★★★ Poor/Avoid
REVIEWS APRIL 97
skyatnightmagazine.com 2014
Bringing you the best in equipment and accessories each month, as reviewed by our team of astro experts
Find out how the huge Meade
LX600 improves on its forebears
98
Reviews
This month’s reviews
First light
98Meade LX600-ACF
12-inch Schmidt-Cassegrain
102William Optics
GTF 102 fve-element astrograph
Books
110We rate
four of the latest astronomy titles
Gear
112 Including this
Baader Classic Q-Eyepiece Set
106QSI 683 WSG-8
CCD camera with in-built flter wheel
SEE INTERACTIVE 360° MODELS OF ALL OUR FIRST LIGHT REVIEWS AT WWW.SKYATNIGHTMAGAZINE.COM
Tried & tested
WW
W.T
hES
ECrE
TSTu
DIO
.nET
X 4
Find out more about how we review equipment at: www.skyatnightmagazine.com/scoring-categories
98
first light
• Price £5,760 with X-Wedge, £5,280 without
• Aperture 305mm (12 inches)
• Focal length 2,438mm (f/8)
• Focuser Internal dual speed 7:1 Crayford-style
• Mount Giant Field tripod
• Controller Autostar II
• Additional features GPS, True Level and North sensors, time chip, planetarium software
• Weight Telescope tube 16.3kg, drive base with fork arms 22.7kg, tripod 22.7kg
• Supplier Telescope House
• www.telescopehouse.com
• Tel 01342 837610
ViTAl STATS The Meade LX600 is, in the
manufacturer’s words, a giant
leap forward in telescope
design, creating a portable,
highly transportable and easy to set up
platform for observation and
astrophotography. We put that to the test
in this review of the 12-inch variant.
In this style of telescope, the tube is
incorporated within a heavy-duty fork
mounting assembly. A Go-To computer is ftted
in the base of the mount. Lifting this arrangement
onto a tripod or equatorial wedge is not for the
fainthearted, although the design of the LX600
does include a means to split the fork arms, so
reducing the component lifting weight.
There are two arm stubs fxed to the optical
tube – these connect to the main forks via two
bolted plates. A locating pin is provided for each
plate. One arm stub can’t be locked and swings
freely, making locating it that bit harder to ft.
Once in place we found it fddly and time-
consuming to ft all eight of the locking hex bolts
and washers in place, and far too easy to drop
them. In the dark this was frustrating.
ww
w.t
hes
ecre
tstu
dio
.net
x 3
words: pete lawrence
stellar starlock
The most innovative aspect of the LX600 system is StarLock. This comprises a wide-feld, 14.7º by 11.8º camera for general pointing and a 3-inch f/5 telescope, giving a 57.2 arcminute by 45.8 arcminute autoguiding setup. The StarLock assembly unobtrusively locks onto the main telescope tube and is connected to the main computer via a supplied cable.
Upon activating the Go-To, the wide-feld camera automatically locates a nearby bright star, which is initially centred. The scope then slews to the selected object, at which point the autoguider locks on. The whole process takes a bit longer than a direct Go-To, but the accuracy is better as a result. StarLock is described as producing arcsecond guiding accuracy, although conditions and set-up precision may affect this.
The system’s activity is indicated by a rather comforting red LED. Once we’d balanced the optical tube and set the guide rate, the system did the rest. Thanks to StarLock, the LX600 range offers large aperture telescopes with camera-enhanced Go-To capability and autoguiding for long-exposure astrophotography. That’s a pretty exciting prospect.
A bridge connection, via a pair of
nine-pin D-plug leads, is required to
allow the Go-To computer at the base
of the forks to communicate with the
declination drives across the fork
breaks. Another eight fddly thumb
screws need to be tightened to ensure
a good connection.
Our test setup included a sturdy
feld tripod, which is included, and an
optional Meade X-Wedge. This is a satisfyingly solid,
angled platform used to convert the LX600’s altaz fork
mount to equatorial mode for long-exposure imaging.
High-precision pointingThe LX600 includes a new feature known as
StarLock, which enables high-precision pointing
accuracy and autoguiding functionality. For
StarLock to work correctly, the telescope tube must
be well balanced. Rail-mounted counterweights
are provided to achieve this, but they require a
hex key to adjust their position – thumb screws
would have been better. We also found that we
had to adjust our guide rate to fairly low to stop
the StarLock from overcompensating. >
smart upgrades and refnements characterise this huge telescope
Schmidt-CassegrainSky SAyS…
The Meade LX600 is a formidable imaging platform despite its fddly set-up process
Meade LX600-ACF 12-inch
see an interactive 360° model of this scope at www.skyatnightmagazine.com/meadelx600
98
first light
• Price £5,760 with X-Wedge, £5,280 without
• Aperture 305mm (12 inches)
• Focal length 2,438mm (f/8)
• Focuser Internal dual speed 7:1 Crayford-style
• Mount Giant Field tripod
• Controller Autostar II
• Additional features GPS, True Level and North sensors, time chip, planetarium software
• Weight Telescope tube 16.3kg, drive base with fork arms 22.7kg, tripod 22.7kg
• Supplier Telescope House
• www.telescopehouse.com
• Tel 01342 837610
ViTAl STATS The Meade LX600 is, in the
manufacturer’s words, a giant
leap forward in telescope
design, creating a portable,
highly transportable and easy to set up
platform for observation and
astrophotography. We put that to the test
in this review of the 12-inch variant.
In this style of telescope, the tube is
incorporated within a heavy-duty fork
mounting assembly. A Go-To computer is ftted
in the base of the mount. Lifting this arrangement
onto a tripod or equatorial wedge is not for the
fainthearted, although the design of the LX600
does include a means to split the fork arms, so
reducing the component lifting weight.
There are two arm stubs fxed to the optical
tube – these connect to the main forks via two
bolted plates. A locating pin is provided for each
plate. One arm stub can’t be locked and swings
freely, making locating it that bit harder to ft.
Once in place we found it fddly and time-
consuming to ft all eight of the locking hex bolts
and washers in place, and far too easy to drop
them. In the dark this was frustrating.
ww
w.t
hes
ecre
tstu
dio
.net
x 3
words: pete lawrence
stellar starlock
The most innovative aspect of the LX600 system is StarLock. This comprises a wide-feld, 14.7º by 11.8º camera for general pointing and a 3-inch f/5 telescope, giving a 57.2 arcminute by 45.8 arcminute autoguiding setup. The StarLock assembly unobtrusively locks onto the main telescope tube and is connected to the main computer via a supplied cable.
Upon activating the Go-To, the wide-feld camera automatically locates a nearby bright star, which is initially centred. The scope then slews to the selected object, at which point the autoguider locks on. The whole process takes a bit longer than a direct Go-To, but the accuracy is better as a result. StarLock is described as producing arcsecond guiding accuracy, although conditions and set-up precision may affect this.
The system’s activity is indicated by a rather comforting red LED. Once we’d balanced the optical tube and set the guide rate, the system did the rest. Thanks to StarLock, the LX600 range offers large aperture telescopes with camera-enhanced Go-To capability and autoguiding for long-exposure astrophotography. That’s a pretty exciting prospect.
A bridge connection, via a pair of
nine-pin D-plug leads, is required to
allow the Go-To computer at the base
of the forks to communicate with the
declination drives across the fork
breaks. Another eight fddly thumb
screws need to be tightened to ensure
a good connection.
Our test setup included a sturdy
feld tripod, which is included, and an
optional Meade X-Wedge. This is a satisfyingly solid,
angled platform used to convert the LX600’s altaz fork
mount to equatorial mode for long-exposure imaging.
High-precision pointingThe LX600 includes a new feature known as
StarLock, which enables high-precision pointing
accuracy and autoguiding functionality. For
StarLock to work correctly, the telescope tube must
be well balanced. Rail-mounted counterweights
are provided to achieve this, but they require a
hex key to adjust their position – thumb screws
would have been better. We also found that we
had to adjust our guide rate to fairly low to stop
the StarLock from overcompensating. >
smart upgrades and refnements characterise this huge telescope
Schmidt-CassegrainSky SAyS…
The Meade LX600 is a formidable imaging platform despite its fddly set-up process
Meade LX600-ACF 12-inch
see an interactive 360° model of this scope at www.skyatnightmagazine.com/meadelx600
skyatnightmagazine.com 2014
first light april 99
Zero-SHiFT FoCuSer
Meade has redesigned its old LX-range focuser to produce a new
mechanism that keeps the target frmly in view while focus is adjusted.
This overcomes a shortcoming of previous designs where the image could shift out of view as the focus
was adjusted. The new design offers coarse and fne (7:1) focus options.
X-Wedge
Meade’s newest equatorial wedge, this heavy-duty platform tilts the base of the LX600 forks so that the RA axis points at the north celestial pole. Fine adjustment is made through altitude and azimuth knobs.
AuToSTAr ii CoMpuTeriSed go-To
As with earlier models, the LX600 is equipped with the Meade Autostar II computerised controller. This system gives you telescope set-up and confguration options, as well as a database of 145,000 objects, which can be centred on at the touch of a few buttons.
SpLiT-Fork
deSign
Like the LX200 range before it, LX600 telescopes are heavy. Meade has engineered a clever way to separate the optical tube from the main forks, allowing the 12-inch LX600 to be just about assembled by one person. However, certain design aspects make the process of putting the scope back together a bit fddly.
skyatnightmagazine.com 2014
first light april 99
Zero-SHiFT FoCuSer
Meade has redesigned its old LX-range focuser to produce a new
mechanism that keeps the target frmly in view while focus is adjusted.
This overcomes a shortcoming of previous designs where the image could shift out of view as the focus
was adjusted. The new design offers coarse and fne (7:1) focus options.
X-Wedge
Meade’s newest equatorial wedge, this heavy-duty platform tilts the base of the LX600 forks so that the RA axis points at the north celestial pole. Fine adjustment is made through altitude and azimuth knobs.
AuToSTAr ii CoMpuTeriSed go-To
As with earlier models, the LX600 is equipped with the Meade Autostar II computerised controller. This system gives you telescope set-up and confguration options, as well as a database of 145,000 objects, which can be centred on at the touch of a few buttons.
SpLiT-Fork
deSign
Like the LX200 range before it, LX600 telescopes are heavy. Meade has engineered a clever way to separate the optical tube from the main forks, allowing the 12-inch LX600 to be just about assembled by one person. However, certain design aspects make the process of putting the scope back together a bit fddly.
F/8 opTiCS
Another departure from earlier LX200 models is the use of f/8 rather than f/10 optics. This delivers a wider and brighter feld of view, allowing the scope to produce decent images of deep-sky objects as well as still keeping a good image scale for Solar System imaging and viewing.
Þ Our composite shot of M42 turned out beautifully
Þ Starlock-guided M82 plus the January 2014 supernova
ww
w.t
hesec
rets
tud
io.n
et,
pete
la
wren
ce x
2
100 first light april
first light
The Advanced Coma-Free (ACF) optics are a
delight to use. A view of the Orion Nebula gave lots
of beautiful detail in the swirling gas cloud, while
the tight trapezium star cluster took the guise of
diamonds scattered in ‘cotton wool’. Dark mottles
and edges of the nebula stood out superbly in the
high-contrast view and it was easy to get lost in the
sumptuous detail. Planetary imaging with the LX600
is really good, as StarLock helps to keep your target
centred in the feld of view. This would be a dream
system for taking planetary timelapse sequences.
A major criticism of previous LX models was the
image shift caused by the focuser. This has been fxed
for the LX600 – the focuser has been revamped
completely – and we didn’t experience any image shift
whatsoever. The focus knob is a little stiff though,
so for accurate high-magnifcation focusing we’d
recommend investing in an in-line electric focuser.
Further improvementsThe mount drives use large, 5.75-inch gears to help
maintain accuracy and provide smooth movements
without serious periodic error. Another great feature
of this setup is the way that it has been designed to
work from horizon-to-horizon without the need for
a meridian fip as the scope passes through the
north-south plane, something that some much more
expensive setups continue to experience.
Unlike previous LX folded-optic designs, the LX600
is f/8 rather than f/10. This gives a bigger, brighter
image and a wider natural feld of view. It also reduces
the tolerance required to maintain good pointing
accuracy for long exposures. If you’re a planetary or
lunar imager, the generous 2.4m focal length will still
offer good image scale without an optical amplifer.
The Meade LX600 is a formidable astro-imaging
platform despite its set-up process being awkward
and a little fddly. Counterweight thumb screws
instead of hex bolts and a better split-fork coupling
would really help the system achieve its goal as a
portable system. S
skyatnightmagazine.com 2014
Verdict
Build And deSign ★★★★★
eASe OF uSe ★★★★★
FeATuReS ★★★★★
gO-TO/TRACking ACCuRACy ★★★★★
OPTiCS ★★★★★
OVeRAll ★★★★★
Sky SAyS… Now add these:
1. Meade zero image shift microfocuser
2. Explore Scientifc 3-inch 0.7x reducer-corrector
3. Revelation Quartz 2-inch dielectric diagonal
>
F/8 opTiCS
Another departure from earlier LX200 models is the use of f/8 rather than f/10 optics. This delivers a wider and brighter feld of view, allowing the scope to produce decent images of deep-sky objects as well as still keeping a good image scale for Solar System imaging and viewing.
Þ Our composite shot of M42 turned out beautifully
Þ Starlock-guided M82 plus the January 2014 supernova
ww
w.t
hesec
rets
tud
io.n
et,
pete
la
wren
ce x
2
100 first light april
first light
The Advanced Coma-Free (ACF) optics are a
delight to use. A view of the Orion Nebula gave lots
of beautiful detail in the swirling gas cloud, while
the tight trapezium star cluster took the guise of
diamonds scattered in ‘cotton wool’. Dark mottles
and edges of the nebula stood out superbly in the
high-contrast view and it was easy to get lost in the
sumptuous detail. Planetary imaging with the LX600
is really good, as StarLock helps to keep your target
centred in the feld of view. This would be a dream
system for taking planetary timelapse sequences.
A major criticism of previous LX models was the
image shift caused by the focuser. This has been fxed
for the LX600 – the focuser has been revamped
completely – and we didn’t experience any image shift
whatsoever. The focus knob is a little stiff though,
so for accurate high-magnifcation focusing we’d
recommend investing in an in-line electric focuser.
Further improvementsThe mount drives use large, 5.75-inch gears to help
maintain accuracy and provide smooth movements
without serious periodic error. Another great feature
of this setup is the way that it has been designed to
work from horizon-to-horizon without the need for
a meridian fip as the scope passes through the
north-south plane, something that some much more
expensive setups continue to experience.
Unlike previous LX folded-optic designs, the LX600
is f/8 rather than f/10. This gives a bigger, brighter
image and a wider natural feld of view. It also reduces
the tolerance required to maintain good pointing
accuracy for long exposures. If you’re a planetary or
lunar imager, the generous 2.4m focal length will still
offer good image scale without an optical amplifer.
The Meade LX600 is a formidable astro-imaging
platform despite its set-up process being awkward
and a little fddly. Counterweight thumb screws
instead of hex bolts and a better split-fork coupling
would really help the system achieve its goal as a
portable system. S
skyatnightmagazine.com 2014
Verdict
Build And deSign ★★★★★
eASe OF uSe ★★★★★
FeATuReS ★★★★★
gO-TO/TRACking ACCuRACy ★★★★★
OPTiCS ★★★★★
OVeRAll ★★★★★
Sky SAyS… Now add these:
1. Meade zero image shift microfocuser
2. Explore Scientifc 3-inch 0.7x reducer-corrector
3. Revelation Quartz 2-inch dielectric diagonal
>
Solarscope manufacture complete h-alpha telescopes available in
unobstructed 50mm and 60mm apertures as well as a range of h-alpha
lter systems which can convert your existing astronomical telescope into a
high quality solar instrument. H-alpha lter systems are available in
unobstructed 50mm, 60mm, 70mm and 100mm aperture sizes.
The dedicated Solarview (SV) telescope range provides you with
everything you need to observe the Sun in h-alpha apart from a mount and
clear skies! These solar instruments are manufactured to the highest
quality and will give you views of our nearest star which will literally take
your breath away.
Observing the Sun through an h-alpha fi lter is an incredible experience…
The solar lter system (SF) range consists of a totally unobstructed front mounted etalon with a matching rear mounted blocking lter which ts
into your telescope’s eyepiece holder. A custom made adapter plate is used to securely mount the etalon over the front of your telescope. Using
laser industry techniques our lter systems are manufactured to the highest optical tolerances.
07624 435572 info@solarscope.co.uk www.solarscope.co.uk
Prestige hydrogen-alpha solar lters manufactured in the Isle of Man
For information on Solarscope fi lters Contact: Ken Huggett
Solarscope manufacture complete h-alpha telescopes available in
unobstructed 50mm and 60mm apertures as well as a range of h-alpha
lter systems which can convert your existing astronomical telescope into a
high quality solar instrument. H-alpha lter systems are available in
unobstructed 50mm, 60mm, 70mm and 100mm aperture sizes.
The dedicated Solarview (SV) telescope range provides you with
everything you need to observe the Sun in h-alpha apart from a mount and
clear skies! These solar instruments are manufactured to the highest
quality and will give you views of our nearest star which will literally take
your breath away.
Observing the Sun through an h-alpha fi lter is an incredible experience…
The solar lter system (SF) range consists of a totally unobstructed front mounted etalon with a matching rear mounted blocking lter which ts
into your telescope’s eyepiece holder. A custom made adapter plate is used to securely mount the etalon over the front of your telescope. Using
laser industry techniques our lter systems are manufactured to the highest optical tolerances.
07624 435572 info@solarscope.co.uk www.solarscope.co.uk
Prestige hydrogen-alpha solar lters manufactured in the Isle of Man
For information on Solarscope fi lters Contact: Ken Huggett
102
skyatnightmagazine.com 2014
first light
• Price £1,669
• Optics FPL53 triplet with rear two-element feld fattener
• Aperture 102mm (4 inches)
• Focal length 703mm (f/6.9)
• Length 786mm with dew shield extended, 659mm with dew shield retracted
• Focuser 2.5-inch dual-speed 10:1 rack and pinion
• Extras Tube rings
• Weight 5kg excluding tube rings
• Supplier The Widescreen Centre
• www.widescreen-centre.co.uk
• Tel 020 7935 2580
ViTAL STATS
William Optics produces two versions
of its 4-inch apo refractor: one a
conventional triplet lens and the
other a fve-element astrograph – it’s
the latter we’re reviewing here. The word astrograph
indicates that the telescope is designed with
astrophotography in mind.
It arrived in a standard cardboard box, but on
opening that up we were greeted by a beautifully
made and sturdy case with ample padding to protect
the telescope in transit. The instrument itself is
strikingly attractive, fnished in an off-white
stippled-powder coat with three contrasting cerise
bands of anodised aluminium.
William Optics has recently changed from
using Crayford focusers to rack and pinion
alternatives, and the 2.5-inch unit supplied
with the review telescope worked smoothly
and fawlessly. With a maximum extension
of 80mm there is plenty of focus travel, but
not knowing exactly where the sensor would
be when we achieved focus we inserted a 50.8mm
extension tube in front of our camera and off-axis
guider. This turned out to be a pretty good guess
– we achieved crisp focus at an extension of just
18mm, which left plenty of the focus tube within
the focuser for stability.
The focuser easily handled the weight of our
imaging system using both the coarse and fne focus
knobs, and there was only the smallest amount of
all
ph
oto
s: w
ww
.th
esec
rets
tud
io.n
et
words: steve richards
quintet of quality
The GTF 102 astrograph has an unusual optical system, comprising fve elements arranged in two groups. The primary lens is an air-spaced triplet that uses FPL53 extra-low dispersion glass to bring all the colours of light to the same focus point. This is important to avoid chromatic aberration, which results in unwanted coloured halos around bright objects. The three lens elements are housed in a fully adjustable, CNC-machined lens cell.
The second group is made up of two lens elements (also made from extra-low dispersion glass), which are set inside the telescope tube. They act as a feld fattener to combat the feld curvature that is normally present in a refractor. Field curvature causes stars at the edges of the feld of view to appear elongated, which is a particular problem in deep-sky imaging.
All of the lens surfaces are fully multicoated to increase light transmission and reduce unwanted refections. Since the feld fattener is built in, there is no critical spacing issue when using a camera, so installing a flter wheel and an off-axis guider is straightforward.
image shift when we tightened up the locking bolt
once we had achieved focus.
The telescope produced a feld of view 1° and 54
arcminutes wide by 1° and 16 arcminutes deep with
our test camera, a one-shot-colour CCD with an
APS-C sensor. This area is just large enough to
capture the Rosette Nebula and some surrounding
stars. With a focal ratio of f/6.9, this telescope is
relatively slow compared to many astrographs,
but this does have some advantages – chromatic
aberration and feld curvature are slightly easier
to control with longer focal length lenses.
Shapely starsAs the CCD camera we used for this review had an
APS-C sensor, the star shapes in our images are a
good indicator for what to expect with a typical
DSLR camera, which has a very similarly sized
sensor. We were very pleasantly surprised by the
shape of the stars across the feld of view
and right into the corners. The
two-element internal feld
fattener was certainly
doing its job
An exciting imaging scope that performs just as well visually
fve-element astrographWilliam Optics GTF 102
>
see an interactive 360° model of this telescope at www.skyatnightmagazine.com/wogtf102
102
skyatnightmagazine.com 2014
first light
• Price £1,669
• Optics FPL53 triplet with rear two-element feld fattener
• Aperture 102mm (4 inches)
• Focal length 703mm (f/6.9)
• Length 786mm with dew shield extended, 659mm with dew shield retracted
• Focuser 2.5-inch dual-speed 10:1 rack and pinion
• Extras Tube rings
• Weight 5kg excluding tube rings
• Supplier The Widescreen Centre
• www.widescreen-centre.co.uk
• Tel 020 7935 2580
ViTAL STATS
William Optics produces two versions
of its 4-inch apo refractor: one a
conventional triplet lens and the
other a fve-element astrograph – it’s
the latter we’re reviewing here. The word astrograph
indicates that the telescope is designed with
astrophotography in mind.
It arrived in a standard cardboard box, but on
opening that up we were greeted by a beautifully
made and sturdy case with ample padding to protect
the telescope in transit. The instrument itself is
strikingly attractive, fnished in an off-white
stippled-powder coat with three contrasting cerise
bands of anodised aluminium.
William Optics has recently changed from
using Crayford focusers to rack and pinion
alternatives, and the 2.5-inch unit supplied
with the review telescope worked smoothly
and fawlessly. With a maximum extension
of 80mm there is plenty of focus travel, but
not knowing exactly where the sensor would
be when we achieved focus we inserted a 50.8mm
extension tube in front of our camera and off-axis
guider. This turned out to be a pretty good guess
– we achieved crisp focus at an extension of just
18mm, which left plenty of the focus tube within
the focuser for stability.
The focuser easily handled the weight of our
imaging system using both the coarse and fne focus
knobs, and there was only the smallest amount of
all
ph
oto
s: w
ww
.th
esec
rets
tud
io.n
et
words: steve richards
quintet of quality
The GTF 102 astrograph has an unusual optical system, comprising fve elements arranged in two groups. The primary lens is an air-spaced triplet that uses FPL53 extra-low dispersion glass to bring all the colours of light to the same focus point. This is important to avoid chromatic aberration, which results in unwanted coloured halos around bright objects. The three lens elements are housed in a fully adjustable, CNC-machined lens cell.
The second group is made up of two lens elements (also made from extra-low dispersion glass), which are set inside the telescope tube. They act as a feld fattener to combat the feld curvature that is normally present in a refractor. Field curvature causes stars at the edges of the feld of view to appear elongated, which is a particular problem in deep-sky imaging.
All of the lens surfaces are fully multicoated to increase light transmission and reduce unwanted refections. Since the feld fattener is built in, there is no critical spacing issue when using a camera, so installing a flter wheel and an off-axis guider is straightforward.
image shift when we tightened up the locking bolt
once we had achieved focus.
The telescope produced a feld of view 1° and 54
arcminutes wide by 1° and 16 arcminutes deep with
our test camera, a one-shot-colour CCD with an
APS-C sensor. This area is just large enough to
capture the Rosette Nebula and some surrounding
stars. With a focal ratio of f/6.9, this telescope is
relatively slow compared to many astrographs,
but this does have some advantages – chromatic
aberration and feld curvature are slightly easier
to control with longer focal length lenses.
Shapely starsAs the CCD camera we used for this review had an
APS-C sensor, the star shapes in our images are a
good indicator for what to expect with a typical
DSLR camera, which has a very similarly sized
sensor. We were very pleasantly surprised by the
shape of the stars across the feld of view
and right into the corners. The
two-element internal feld
fattener was certainly
doing its job
An exciting imaging scope that performs just as well visually
fve-element astrographWilliam Optics GTF 102
>
see an interactive 360° model of this telescope at www.skyatnightmagazine.com/wogtf102
skyatnightmagazine.com 2014
first light APRIL 103
Sky SAyS…
All of the lens surfaces are fully multicoated to increase light transmission and reduce unwanted refections
Rack and PiniOn
FOcuSeR
The 2.5-inch rack and pinion focuser has anti-marring brass
compression rings, can be rotated through 360° and is very
smooth in operation, with minimal image shift when applying the
simple lock mechanism. The 10:1 two-speed mechanism handled
the weight of our imaging camera, off-axis guider and
guide camera with ease.
ReTRacTable deW Shield
The 127mm-long dew shield does an excellent job of defecting extraneous light and keeping the dew at bay. The front is capped with an aluminium dust cover that simply and safely slips on and off. A convenient thumbscrew locks the shield in its extended position.
Tube RinGS
The 105mm diameter, CNC-machined tube rings have a crisp, black crackle fnish. With a choice of mounting holes in both upper and lower mountings, they accommodate various types of dovetail bar and accessories. Nylon spacers on the locking bolts help to protect the clamp surfaces.
TeleScOPe Tube
The construction of the telescope tube, which is machined from aluminium, underpins the optical system’s stability – the whole telescope felt very solid indeed. Internally the tube is fnished in matt black and has three knife-edge baffes, which together help to reduce internal refections and increase the contrast of the view.
skyatnightmagazine.com 2014
first light APRIL 103
Sky SAyS…
All of the lens surfaces are fully multicoated to increase light transmission and reduce unwanted refections
Rack and PiniOn
FOcuSeR
The 2.5-inch rack and pinion focuser has anti-marring brass
compression rings, can be rotated through 360° and is very
smooth in operation, with minimal image shift when applying the
simple lock mechanism. The 10:1 two-speed mechanism handled
the weight of our imaging camera, off-axis guider and
guide camera with ease.
ReTRacTable deW Shield
The 127mm-long dew shield does an excellent job of defecting extraneous light and keeping the dew at bay. The front is capped with an aluminium dust cover that simply and safely slips on and off. A convenient thumbscrew locks the shield in its extended position.
Tube RinGS
The 105mm diameter, CNC-machined tube rings have a crisp, black crackle fnish. With a choice of mounting holes in both upper and lower mountings, they accommodate various types of dovetail bar and accessories. Nylon spacers on the locking bolts help to protect the clamp surfaces.
TeleScOPe Tube
The construction of the telescope tube, which is machined from aluminium, underpins the optical system’s stability – the whole telescope felt very solid indeed. Internally the tube is fnished in matt black and has three knife-edge baffes, which together help to reduce internal refections and increase the contrast of the view.
ww
w.t
hesec
rets
tud
io.n
et,
ste
ve r
ich
ard
s
first light
Verdict
BuiLd And dESign ★★★★★
EASE OF uSE ★★★★★
FEATurES ★★★★★
imAging QuALiTy ★★★★★
OPTicS ★★★★★
OVErALL ★★★★★
and so too was the triplet lens, as chromatic
aberration was also well controlled. There was
some vignetting, which caused the edges of the
feld of view to be darker than the centre, but this
was easily corrected by calibrating the images
with suitable fat frames. One problem that can
occur with multi-element designs like this is
that of focus shift with temperature change.
However, we didn’t fnd it necessary to adjust
focus during our 4.5-hour imaging session
despite a thick frost forming on the inside of
our domed observatory.
Although the GTF 102 is designed as an
astrograph, we couldn’t resist using it for some
simple observing and we weren’t disappointed.
Using our own 2-inch dielectric diagonal and
eyepieces we enjoyed some glorious views of
Jupiter and the gibbous Moon.
The lack of false colour in our imaging tests was
corroborated through the eyepiece. Confrmed too
were excellent star shapes right out to the edge of
the feld of view. We couldn’t ignore the presence
of the Orion Nebula and the large swathe of
nebulosity observed through our 17mm eyepiece
was particularly memorable, as was the crisp,
sparkly view of the Pleiades star cluster.
We thoroughly enjoyed our experiences with the
GTF 102 and would recommend the telescope to
any astrophotographer searching for an imaging
instrument that removes the pain of achieving a fat
feld with stars pin sharp to the edge.
skyatnightmagazine.com 2014
SOFT caSe
The GTF 102 is supplied with a high-quality soft padded case. It is very substantial and protects the telescope in transit very well indeed. With both carry handles and a shoulder strap, transporting the scope is easy.
Sky SAyS… Now add these:
1. William Optics 50mm guidescope with mounting bracket
2. Atik 383L+ CCD camera
3. Sky-Watcher AZ-EQ6 GT mount and tripod
>
104 first light APRIL
S
Þ Our image of the rosette nebula in monoceros exhibits clean star shapes right to the edges of the feld
ww
w.t
hesec
rets
tud
io.n
et,
ste
ve r
ich
ard
s
first light
Verdict
BuiLd And dESign ★★★★★
EASE OF uSE ★★★★★
FEATurES ★★★★★
imAging QuALiTy ★★★★★
OPTicS ★★★★★
OVErALL ★★★★★
and so too was the triplet lens, as chromatic
aberration was also well controlled. There was
some vignetting, which caused the edges of the
feld of view to be darker than the centre, but this
was easily corrected by calibrating the images
with suitable fat frames. One problem that can
occur with multi-element designs like this is
that of focus shift with temperature change.
However, we didn’t fnd it necessary to adjust
focus during our 4.5-hour imaging session
despite a thick frost forming on the inside of
our domed observatory.
Although the GTF 102 is designed as an
astrograph, we couldn’t resist using it for some
simple observing and we weren’t disappointed.
Using our own 2-inch dielectric diagonal and
eyepieces we enjoyed some glorious views of
Jupiter and the gibbous Moon.
The lack of false colour in our imaging tests was
corroborated through the eyepiece. Confrmed too
were excellent star shapes right out to the edge of
the feld of view. We couldn’t ignore the presence
of the Orion Nebula and the large swathe of
nebulosity observed through our 17mm eyepiece
was particularly memorable, as was the crisp,
sparkly view of the Pleiades star cluster.
We thoroughly enjoyed our experiences with the
GTF 102 and would recommend the telescope to
any astrophotographer searching for an imaging
instrument that removes the pain of achieving a fat
feld with stars pin sharp to the edge.
skyatnightmagazine.com 2014
SOFT caSe
The GTF 102 is supplied with a high-quality soft padded case. It is very substantial and protects the telescope in transit very well indeed. With both carry handles and a shoulder strap, transporting the scope is easy.
Sky SAyS… Now add these:
1. William Optics 50mm guidescope with mounting bracket
2. Atik 383L+ CCD camera
3. Sky-Watcher AZ-EQ6 GT mount and tripod
>
104 first light APRIL
S
Þ Our image of the rosette nebula in monoceros exhibits clean star shapes right to the edges of the feld
f1telescopesQuality advice • excellent service • competitive prices
Celestron, Baader
Planetarium, meade,
skywatCher, Vixen, Coronado
and more…
Part exchange welcome.
we also buy and sell used telescopes and
provide service and repair facilities.
visit our shop at:
unit a3, st GeorGe’s Business Park,
Castle road, sittinGBourne, kent
me10 3tB. 01795 432702
check out our website:
www.f1telescopes.co.uk
the only astro sPeCialist in kent
A large range of telescopes and accessories from the world’s leading suppliers.
Tel: 01903 247317 • 16 Mulberry Lane, Goring-by-Sea, Worthing, West Sussex
www.sussex-astronomy-centre.co.uk
Free Parking
Friendly personal service for ALL your astronomy needs.
Beginners most welcome!
Sussex Astronomy Centre Meade Advanced Product Dealer
Celestron, Sky-Watcher, Meade main stockist for Sussex
Friendly Advice and After-Sales Service.
www.green-witch.com
Buy online with confdence or visit our well stocked showrooms.
Birstall, West YorksWF17 9ES
01924 477719
Gransden, Beds & CambsSG19 3PF
01767 677025
Astronomy
Roudham • NoRfolk NR16 2QN
01953 423111 / 07967 376336
specialists in the construction and installation
of rolling roof observatories and telescope
piers for the home astronomer.
Friendly and Reliable Service.
www.homeobservatoryuk.com
home obseRvatoRy uk
Any Size • Warm Rooms Wheelchair/Disabled Access • Electric Roof
Visit uS at
f1telescopesQuality advice • excellent service • competitive prices
Celestron, Baader
Planetarium, meade,
skywatCher, Vixen, Coronado
and more…
Part exchange welcome.
we also buy and sell used telescopes and
provide service and repair facilities.
visit our shop at:
unit a3, st GeorGe’s Business Park,
Castle road, sittinGBourne, kent
me10 3tB. 01795 432702
check out our website:
www.f1telescopes.co.uk
the only astro sPeCialist in kent
A large range of telescopes and accessories from the world’s leading suppliers.
Tel: 01903 247317 • 16 Mulberry Lane, Goring-by-Sea, Worthing, West Sussex
www.sussex-astronomy-centre.co.uk
Free Parking
Friendly personal service for ALL your astronomy needs.
Beginners most welcome!
Sussex Astronomy Centre Meade Advanced Product Dealer
Celestron, Sky-Watcher, Meade main stockist for Sussex
Friendly Advice and After-Sales Service.
www.green-witch.com
Buy online with confdence or visit our well stocked showrooms.
Birstall, West YorksWF17 9ES
01924 477719
Gransden, Beds & CambsSG19 3PF
01767 677025
Astronomy
Roudham • NoRfolk NR16 2QN
01953 423111 / 07967 376336
specialists in the construction and installation
of rolling roof observatories and telescope
piers for the home astronomer.
Friendly and Reliable Service.
www.homeobservatoryuk.com
home obseRvatoRy uk
Any Size • Warm Rooms Wheelchair/Disabled Access • Electric Roof
Visit uS at
Tried & tested
• Price £3,149
• Size 141x149x84mm
• Sensor Truesense Imaging KAF-8300
• Sensor size 17.96x13.52mm, 22.5mm diagonal
• Pixels 3326 x 2504
• Back focus 50.2mm
• Weight 1.66kg
• Extras Peli case, AC mains power supply, USB cable, ST4 cable, Allen keys, 2-inch nosepiece adaptor, CD
• Supplier Ian King Imaging
• www.iankingimaging.com
• Tel 01580 212356
ViTal STaTS
Astrophotography has rightly become
a very important and enjoyable aspect
of astronomy: it is only through
the capture of long-exposure images
that the true colourful beauty and detail of
deep-sky objects can be appreciated. Modern
DSLR cameras can capture this detail and much
of the colour of these objects, but dedicated
astronomical CCDs such as the QSI 683 WSG-8
can do it much better. This is because they have
built-in cooling to reduce thermal noise from the
sensor and are not hampered by infrared flters
designed for daytime use.
The QSI 683 WSG-8 CCD camera, frst released
in 2012, is designed to overcome several of the
issues that cause the most angst among astro
imagers. The inclusion of an integrated flter wheel
and an off-axis guider with enough space to use
with a standard coma corrector, feld fattener or
focal reducer is one of these good ideas.
The camera is supplied in a high-quality Peli
1400 case, giving the contents excellent protection.
Included in the case is an AC mains power supply,
USB cable, ST4 cable, a set of Allen keys, a 2-inch
nosepiece adaptor and a CD. Plug-ins for MaxIm DL,
CCDSoft and AstroArt are included on the CD,
CCD camera
ww
w.t
hes
ecrets
tud
io.n
et
x 4
, ste
ve
ric
ha
rd
s x
2
words: steve richards
106
skyatnightmagazine.com 2014
along with an ASCOM driver and a full set
of well-written and comprehensive manuals.
Plug-ins for other image capture programs are
available for download from the QSI website
(www.QSimaging.com).
Quality manufacturingAt 1.66kg, the camera feels very substantially built
and closer inspection confrms the quality of the
manufacturing. Great attention to detail has been
expended on both the external case and the
internal components, and we couldn’t help but
be impressed with how it all ftted together. The
built-in flter wheel possesses eight slots, which we
populated with our own flters: luminance, red,
green, blue, hydrogen-alpha, oxygen III, sulphur II
and hydrogen-beta. Having such a variety of flters
available at one time makes for very fexible
imaging as it is easy to choose the right flter for
the celestial object at hand.
Deep-sky imaging requires long exposures, so
it is imperative to ensure that your mount tracks
very accurately if you want to avoid stars trails. The
‘G’ in WSG stands for guider – the camera has a
built-in off-axis guider installed in front of the flter
wheel. This very convenient arrangement ensures
QSI 683
Sky SayS…We imaged a range of objects and were very impressed with the sensitivity and lack of thermal noise
We review well-established equipment that’s stood the test of time
A built-in filter wheel and off-axis guider make for a neat package
owner’s observationsName Steve Richardslocation Nr Wiston, West SussexEquipment QSI 683 WSG-8Owner since June 2013
I bought the QSI 683 WSG-8 mono CCD camera specifcally for use on my dual imaging system. I use a mono CCD camera on one telescope and a one-shot colour CCD camera on a second telescope, which allows me to capture two sets of data simultaneously that I can combine later on. My original mono CCD camera had a much smaller sensor (8.98x6.71mm)
than my colour camera and this mismatch reduced the size of my fnished images too much. The larger sensor in the QSI 683 WSG-8 (17.96x13.52mm) allows me to capture much better matched images at a far higher resolution.
Even though the QSI 683 WSG-8’s KAF-8300 sensor was much larger, I was still able to use my existing set of 1.25-inch flters, which was a real advantage in terms of cost. Such was the quality of the data captured by the new camera that it wasn’t long before I started concentrating on using just this camera for most of my imaging.
WSG-8
>
see an interactive 360° model of this camera at www.skyatnightmagazine.com/qsi683
Tried & tested
• Price £3,149
• Size 141x149x84mm
• Sensor Truesense Imaging KAF-8300
• Sensor size 17.96x13.52mm, 22.5mm diagonal
• Pixels 3326 x 2504
• Back focus 50.2mm
• Weight 1.66kg
• Extras Peli case, AC mains power supply, USB cable, ST4 cable, Allen keys, 2-inch nosepiece adaptor, CD
• Supplier Ian King Imaging
• www.iankingimaging.com
• Tel 01580 212356
ViTal STaTS
Astrophotography has rightly become
a very important and enjoyable aspect
of astronomy: it is only through
the capture of long-exposure images
that the true colourful beauty and detail of
deep-sky objects can be appreciated. Modern
DSLR cameras can capture this detail and much
of the colour of these objects, but dedicated
astronomical CCDs such as the QSI 683 WSG-8
can do it much better. This is because they have
built-in cooling to reduce thermal noise from the
sensor and are not hampered by infrared flters
designed for daytime use.
The QSI 683 WSG-8 CCD camera, frst released
in 2012, is designed to overcome several of the
issues that cause the most angst among astro
imagers. The inclusion of an integrated flter wheel
and an off-axis guider with enough space to use
with a standard coma corrector, feld fattener or
focal reducer is one of these good ideas.
The camera is supplied in a high-quality Peli
1400 case, giving the contents excellent protection.
Included in the case is an AC mains power supply,
USB cable, ST4 cable, a set of Allen keys, a 2-inch
nosepiece adaptor and a CD. Plug-ins for MaxIm DL,
CCDSoft and AstroArt are included on the CD,
CCD camera
ww
w.t
hes
ecrets
tud
io.n
et
x 4
, ste
ve
ric
ha
rd
s x
2
words: steve richards
106
skyatnightmagazine.com 2014
along with an ASCOM driver and a full set
of well-written and comprehensive manuals.
Plug-ins for other image capture programs are
available for download from the QSI website
(www.QSimaging.com).
Quality manufacturingAt 1.66kg, the camera feels very substantially built
and closer inspection confrms the quality of the
manufacturing. Great attention to detail has been
expended on both the external case and the
internal components, and we couldn’t help but
be impressed with how it all ftted together. The
built-in flter wheel possesses eight slots, which we
populated with our own flters: luminance, red,
green, blue, hydrogen-alpha, oxygen III, sulphur II
and hydrogen-beta. Having such a variety of flters
available at one time makes for very fexible
imaging as it is easy to choose the right flter for
the celestial object at hand.
Deep-sky imaging requires long exposures, so
it is imperative to ensure that your mount tracks
very accurately if you want to avoid stars trails. The
‘G’ in WSG stands for guider – the camera has a
built-in off-axis guider installed in front of the flter
wheel. This very convenient arrangement ensures
QSI 683
Sky SayS…We imaged a range of objects and were very impressed with the sensitivity and lack of thermal noise
We review well-established equipment that’s stood the test of time
A built-in filter wheel and off-axis guider make for a neat package
owner’s observationsName Steve Richardslocation Nr Wiston, West SussexEquipment QSI 683 WSG-8Owner since June 2013
I bought the QSI 683 WSG-8 mono CCD camera specifcally for use on my dual imaging system. I use a mono CCD camera on one telescope and a one-shot colour CCD camera on a second telescope, which allows me to capture two sets of data simultaneously that I can combine later on. My original mono CCD camera had a much smaller sensor (8.98x6.71mm)
than my colour camera and this mismatch reduced the size of my fnished images too much. The larger sensor in the QSI 683 WSG-8 (17.96x13.52mm) allows me to capture much better matched images at a far higher resolution.
Even though the QSI 683 WSG-8’s KAF-8300 sensor was much larger, I was still able to use my existing set of 1.25-inch flters, which was a real advantage in terms of cost. Such was the quality of the data captured by the new camera that it wasn’t long before I started concentrating on using just this camera for most of my imaging.
WSG-8
>
see an interactive 360° model of this camera at www.skyatnightmagazine.com/qsi683
skyatnightmagazine.com 2014
tried & tested april 107
KAF-8300 SenSor
The KAF-8300 sensor conveniently bridges the gap between the typically affordable but
smaller Sony sensors and their larger and much more expensive APS C or large format counterparts. With 8.3 megapixels across its
surface and generous size (5.4μm) pixels, you can capture wide high-resolution images
without sacrifcing sensitivity.
TWo-STAGe PelTIer CoolInG
The camera uses a two-stage Peltier thermoelectric cooling system with two internal fans and set point cooling to reduce image noise caused by heat from the sensor during long exposures. This system is capable of cooling the sensor down to 45°C below the ambient temperature.
BuIlT-In oFF-AxIS GuIDer
An autoguiding system is vital for accurate tracking during long-exposure imaging; the most accurate way to do this is with an off-axis guider and guide camera. The QSI 683 WSG-8 has a neatly installed off-axis guider in front of the flter wheel, ensuring that only unfltered light reaches the guide camera.
SmAll DePTh
Although the camera incorporates both a flter wheel and an off-axis guider, its total depth from the front mounting plate to the sensor is only 50.2mm. This means that a simple 6mm T-extension tube will make the camera compatible with the industry standard sensor to focal reducer-feld fattener distance of 56mm.
skyatnightmagazine.com 2014
tried & tested april 107
KAF-8300 SenSor
The KAF-8300 sensor conveniently bridges the gap between the typically affordable but
smaller Sony sensors and their larger and much more expensive APS C or large format counterparts. With 8.3 megapixels across its
surface and generous size (5.4μm) pixels, you can capture wide high-resolution images
without sacrifcing sensitivity.
TWo-STAGe PelTIer CoolInG
The camera uses a two-stage Peltier thermoelectric cooling system with two internal fans and set point cooling to reduce image noise caused by heat from the sensor during long exposures. This system is capable of cooling the sensor down to 45°C below the ambient temperature.
BuIlT-In oFF-AxIS GuIDer
An autoguiding system is vital for accurate tracking during long-exposure imaging; the most accurate way to do this is with an off-axis guider and guide camera. The QSI 683 WSG-8 has a neatly installed off-axis guider in front of the flter wheel, ensuring that only unfltered light reaches the guide camera.
SmAll DePTh
Although the camera incorporates both a flter wheel and an off-axis guider, its total depth from the front mounting plate to the sensor is only 50.2mm. This means that a simple 6mm T-extension tube will make the camera compatible with the industry standard sensor to focal reducer-feld fattener distance of 56mm.
that the use of flters
has no effect on the light
falling on the guide
camera, thus ensuring
the greatest chance of
fnding a suitable guide
star even with very short
exposures. An off-axis
guider uses a small
pick-off prism, placed
just outside the cone
of light falling on the
imaging sensor, to
divert light from a
test star to the guide camera for analysis of
unwanted movement and subsequent mount
correction under software control. This provides
a very accurate method of autoguiding.
The short turret on top of the camera’s casing
is machined with a male C-thread, making it
compatible with various guide cameras. Adjustment
of the guide camera’s focus was very simply
carried out by slackening a single grub screw
using one of the supplied Allen keys and rotating
the focus ring around its thread.
The KAF-8300 sensor is a ‘full frame’ chip,
which means that unlike many sensors used
in astronomical CCD cameras it requires a
mechanical shutter, and the one used in the
QSI 683 WSG-8 operates quietly and smoothly.
We imaged a range of objects with the camera and
were very impressed with its sensitivity and lack
of thermal noise during exposures of up to
20 minutes. We would thoroughly recommend
the QSI 683 WSG-8 to intermediate or advanced
astrophotographers looking to upgrade to an
all-in-one mono camera, flter wheel and
off-axis guider imaging solution.
stev
e r
ich
ard
s x
3
108 tried & tested april
Tried & tested
BuIlT-In FIlTer Wheel
Despite the camera’s relatively large sensor, it only requires 1.25-inch flters. Up to eight of these can be installed in the built-in flter wheel at a time. Because the flter wheel is integrated into the camera, only one power cable and one USB cable are required, which cuts down on the usual tangle of wires.
S
skyatnightmagazine.com 2014
Verdict
Build aNd dESigN ★★★★★
CONNECTiViTy ★★★★★
EaSE Of uSE ★★★★★
fEaTurES ★★★★★
imagiNg QualiTy ★★★★★
OVErall ★★★★★
Sky SayS… Now add these:
1. Starlight Xpress Lodestar autoguider
2. QSI EOS lens adaptor
3. QSI C mount lens adaptor
Our composite shot of NgC 6888, comprised of
seven 600-second frames: fve in Ha and two in Oiii
The Cygnus loop in Ha; the large flter wheel makes it easy to pick the right wavelength for the job
>
that the use of flters
has no effect on the light
falling on the guide
camera, thus ensuring
the greatest chance of
fnding a suitable guide
star even with very short
exposures. An off-axis
guider uses a small
pick-off prism, placed
just outside the cone
of light falling on the
imaging sensor, to
divert light from a
test star to the guide camera for analysis of
unwanted movement and subsequent mount
correction under software control. This provides
a very accurate method of autoguiding.
The short turret on top of the camera’s casing
is machined with a male C-thread, making it
compatible with various guide cameras. Adjustment
of the guide camera’s focus was very simply
carried out by slackening a single grub screw
using one of the supplied Allen keys and rotating
the focus ring around its thread.
The KAF-8300 sensor is a ‘full frame’ chip,
which means that unlike many sensors used
in astronomical CCD cameras it requires a
mechanical shutter, and the one used in the
QSI 683 WSG-8 operates quietly and smoothly.
We imaged a range of objects with the camera and
were very impressed with its sensitivity and lack
of thermal noise during exposures of up to
20 minutes. We would thoroughly recommend
the QSI 683 WSG-8 to intermediate or advanced
astrophotographers looking to upgrade to an
all-in-one mono camera, flter wheel and
off-axis guider imaging solution.
stev
e r
ich
ard
s x
3
108 tried & tested april
Tried & tested
BuIlT-In FIlTer Wheel
Despite the camera’s relatively large sensor, it only requires 1.25-inch flters. Up to eight of these can be installed in the built-in flter wheel at a time. Because the flter wheel is integrated into the camera, only one power cable and one USB cable are required, which cuts down on the usual tangle of wires.
S
skyatnightmagazine.com 2014
Verdict
Build aNd dESigN ★★★★★
CONNECTiViTy ★★★★★
EaSE Of uSE ★★★★★
fEaTurES ★★★★★
imagiNg QualiTy ★★★★★
OVErall ★★★★★
Sky SayS… Now add these:
1. Starlight Xpress Lodestar autoguider
2. QSI EOS lens adaptor
3. QSI C mount lens adaptor
Our composite shot of NgC 6888, comprised of
seven 600-second frames: fve in Ha and two in Oiii
The Cygnus loop in Ha; the large flter wheel makes it easy to pick the right wavelength for the job
>
110
skyatnightmagazine.com 2014
BooksRATINGS
★★★★★ Outstanding ★★★★★ Good ★★★★★ Average★★★★★ Poor★★★★★ Avoid
Two minuTes
wiTh DaviD
walTham
What inspired you to write the book?Ten years ago it occurred
to me that the simple question ‘Is Earth an unusual planet?’ brought my passions of astronomy and geology together. We can’t understand Earth properly without answering this question and we can’t do that without looking at how our world fts into the wider Universe.
Do you think life has evolved elsewhere?Defnitely. The basic idea behind Lucky Planet is that the Universe is so large that even very odd places like Earth are inevitable. I think Earth is so rare that we’re unlikely to ever fnd another world with a biosphere as complex as ours; the fip side of this argument is that there are probably many such places scattered across the Universe. It’s just that they are so far apart they are forever isolated from each other.
What makes a planet ‘lucky’?It’s not that any single property is rare; it’s the combination of many slightly unusual properties. If one in 10 planets are the right size and one in 10 planets orbit at the right distance and one in 10 planets have the right amount of water… you can see where I’m going with this. What do you think about the latest exoplanet searches?Despite all I’ve said, I’m a huge supporter of the ongoing hunt for exoplanets. I think the data we have at present points to habitable worlds being rare, but that’s based on very little data. What we need is more information, which will hopefully prove my pessimism to be misplaced.
Dr DavID WalTham is a lecturer in mathematical geology at Royal Holloway
You can order these books from our shop by calling 01803 865913
reader price £13.99, subscriber price £12.99P&P £1.99 Code: S0414/2
David WalthamIcon £14.99 PB
Earth is exceptional. It is a planet that has
endured around four billion years of good
weather, purely by chance – the luckiest
planet in the visible Universe.
This is the argument of Lucky Planet,
written by University of London geophysicist
David Waltham. Many scientists dismiss
the idea that Earth is special; they favour
suggestions our home is actually mediocre
and that life is widespread throughout
the Universe. As the title suggests,
Waltham disagrees, detailing the many
ways in which Earth has just been very
fortunate indeed.
It is a refreshing angle amid
numerous similar titles
touting the opposing
view. Waltham explores
the various properties
our planet possesses
that have led to
its habitability,
covering astronomy,
biology, cosmology,
climatology,
and geology.
The most interesting
and important consideration
is that in order for Earth to be
how it is now, our planet must
have been potentially habitable
for a very large portion of its history.
While this may seem obvious, it is actually
quite an intriguing perspective – if the
Earth had had slightly more changeable
weather or a marginally different
atmospheric composition at any one
point, it would be an entirely different
planet today.
When it comes to structure, however,
the book is a little unusual. For example,
Waltham focuses for an oddly long time
on climatology and ice ages, and then
moves abruptly on to the idea of music,
later linking this with planetary orbits.
Some of the chapters could perhaps be best
expressed via a timeline, as embedding
copious details about
atmosphere, temperature
and feedback processes
at various stages in
Earth’s history into
dense paragraphs
of text is quite
diffcult to digest.
Although Lucky
Planet contains
several brilliant
analogies and
explanations, at times it
is obvious that Waltham is
a scientist frst and an author
second, as there is a tendency to
cram in technical information
at the expense of readability. However, if
you wish to learn about the climatology of
our planet from its formation to the present
day, it serves as a comprehensive overview.
★★★★★
NICkY GUTTrIDGE is a science journalist and Hubble public information offcer
New astronomy and space titles reviewed
Minute changes could have rendered Earth a very different place
Lucky Planet
110
skyatnightmagazine.com 2014
BooksRATINGS
★★★★★ Outstanding ★★★★★ Good ★★★★★ Average★★★★★ Poor★★★★★ Avoid
Two minuTes
wiTh DaviD
walTham
What inspired you to write the book?Ten years ago it occurred
to me that the simple question ‘Is Earth an unusual planet?’ brought my passions of astronomy and geology together. We can’t understand Earth properly without answering this question and we can’t do that without looking at how our world fts into the wider Universe.
Do you think life has evolved elsewhere?Defnitely. The basic idea behind Lucky Planet is that the Universe is so large that even very odd places like Earth are inevitable. I think Earth is so rare that we’re unlikely to ever fnd another world with a biosphere as complex as ours; the fip side of this argument is that there are probably many such places scattered across the Universe. It’s just that they are so far apart they are forever isolated from each other.
What makes a planet ‘lucky’?It’s not that any single property is rare; it’s the combination of many slightly unusual properties. If one in 10 planets are the right size and one in 10 planets orbit at the right distance and one in 10 planets have the right amount of water… you can see where I’m going with this. What do you think about the latest exoplanet searches?Despite all I’ve said, I’m a huge supporter of the ongoing hunt for exoplanets. I think the data we have at present points to habitable worlds being rare, but that’s based on very little data. What we need is more information, which will hopefully prove my pessimism to be misplaced.
Dr DavID WalTham is a lecturer in mathematical geology at Royal Holloway
You can order these books from our shop by calling 01803 865913
reader price £13.99, subscriber price £12.99P&P £1.99 Code: S0414/2
David WalthamIcon £14.99 PB
Earth is exceptional. It is a planet that has
endured around four billion years of good
weather, purely by chance – the luckiest
planet in the visible Universe.
This is the argument of Lucky Planet,
written by University of London geophysicist
David Waltham. Many scientists dismiss
the idea that Earth is special; they favour
suggestions our home is actually mediocre
and that life is widespread throughout
the Universe. As the title suggests,
Waltham disagrees, detailing the many
ways in which Earth has just been very
fortunate indeed.
It is a refreshing angle amid
numerous similar titles
touting the opposing
view. Waltham explores
the various properties
our planet possesses
that have led to
its habitability,
covering astronomy,
biology, cosmology,
climatology,
and geology.
The most interesting
and important consideration
is that in order for Earth to be
how it is now, our planet must
have been potentially habitable
for a very large portion of its history.
While this may seem obvious, it is actually
quite an intriguing perspective – if the
Earth had had slightly more changeable
weather or a marginally different
atmospheric composition at any one
point, it would be an entirely different
planet today.
When it comes to structure, however,
the book is a little unusual. For example,
Waltham focuses for an oddly long time
on climatology and ice ages, and then
moves abruptly on to the idea of music,
later linking this with planetary orbits.
Some of the chapters could perhaps be best
expressed via a timeline, as embedding
copious details about
atmosphere, temperature
and feedback processes
at various stages in
Earth’s history into
dense paragraphs
of text is quite
diffcult to digest.
Although Lucky
Planet contains
several brilliant
analogies and
explanations, at times it
is obvious that Waltham is
a scientist frst and an author
second, as there is a tendency to
cram in technical information
at the expense of readability. However, if
you wish to learn about the climatology of
our planet from its formation to the present
day, it serves as a comprehensive overview.
★★★★★
NICkY GUTTrIDGE is a science journalist and Hubble public information offcer
New astronomy and space titles reviewed
Minute changes could have rendered Earth a very different place
Lucky Planet
books APRIL 111
skyatnightmagazine.com 2014
Wizards, Aliens and Starships Charles l adler Princeton £19.95 PB
Fans of science-fction
and fantasy tales
usually realise that
they need to suspend
belief and allow
some poetic licence
so that a story may
be told. While
a few authors
try hard to keep
their narratives
within the bounds of scientifc possibility,
others seem to make up new laws of
physics as they go along.
Wizards, Aliens and Starships looks
at many of the common concepts and
plot devices that are used in science
fction and examines the actual science
behind them. There’s a hefty chunk
dealing with the fantasy world of Harry
Potter to get past, but from there on
the book concerns itself with topics
of greater interest to astronomers and
space fans. How easy is it really to travel
vast distances in space, for instance?
What propulsion systems could be used?
What are the practicalities of founding
colonies and terraforming planets?
Will we ever travel faster than light?
What are the chances of fnding and
communicating with ET?
These are just a few of the range of
topics examined by author and professor
of Physics Charles Adler. He says this is
the book he would have wanted to read
as a 15-year-old boy, but offers a word of
warning: that readers should have some
knowledge of algebra and calculus; and
indeed there are many formulae and
equations scattered throughout the
book. Despite this, the writing style is
light and will give sci-f fans a rewarding
and thought-provoking read.
★★★★★
PaUl SUThErlaND is a space writer and journalist
reader price £14.95, subscriber price £13.95 P&P £1.99 Code: S0414/1
Omar W Nasim Chicago £31.50 hB
As befts its subject
matter, Observing by
Hand looks beautiful.
It deals with the
tricky, rather
under-researched
area of observational
astronomy, that
place between
observation and publication. Author Omar
Nasim uses tools from art history as well
as a good understanding of astronomy to
explore this complicated relationship
between art and science; between the eye,
the mind and the hand; between what is
observed and the image produced.
Today astronomy is intertwined with
photography. For a signifcant part of the
19th century, images were produced by hand,
requiring artistic skill, an understanding
of the heavens and an ability to record
detail accurately and quickly. The style of
writing refects the content, being careful
and meticulous, just as the observers were
who produced the images discussed.
Each chapter focuses on different
astronomers and how their approach to
drawing nebulae adds to the bigger story.
Through the work of Lord Rosse and his
assistants John Herschel, EP Mason, William
Lassell and Wilhelm Tempel, we see the
range of techniques used, and the factors
that shaped them. In doing so, Nasim
shows us the role theory played in shaping
what each astronomer saw, the skill
involved in ‘translating’ that onto paper,
and the fuidity of the border between art
and science. For anyone with an interest
and appreciation of the beauty of nebulae,
this is a book that will leave you thinking.
★★★★★
Dr EmIlY WINTErBUrN is a writer and visiting fellow at the University of Leeds
reader price £27.99, subscriber price £26.99 P&P £1.99 Code: S0414/4
John Bromley-Davenport Bene Factum Publishing£20 hB
Sir Bernard lovell was one of the most eminent British scientists of the past hundred years. a pioneer of radar techniques, originator of Jodrell Bank
Observatory and a popular orator of the physical sciences, his legacy is immense.
This biography by family friend John Bromley-Davenport, coming little more than a year after lovell’s death, is an insightful and detailed account of the astronomer’s life. Using carefully researched original documents, and peppered with personal anecdotes from lovell himself, Bromley-Davenport gives a fascinating profle of the man, his science, his beliefs, and his trials and tribulations.
although many of the basic details of lovell’s life are available elsewhere, this offering digs a little deeper into some of the major events of his life. The account of lovell’s wartime radar development is excellent, flling in hitherto unpublished details. The stresses and strains during the design and construction of the 76m radio telescope at Jodrell Bank that bears lovell’s name are ably portrayed. lovell’s involvement with certain secretive aspects of the Cold War are well known, but this account contains new facts based on recently released offcial records.
The assertion that lovell was duped by a committed marxist into believing he was an undercover government agent seems both incongruous and speculative. So too is the inference that lovell himself was a spy. Nevertheless, this biography is a fascinating and scholarly read.★★★★★
Dr alaSTaIr GUNN is a radio astronomer at Jodrell Bank Observatory in Cheshire
reader price £18.99, subscriber price £17.99 P&P £1.99 Code: S0414/3
Space Has No FrontierThe Terrestrial Life and Times of Sir Bernard Lovell
Observing by Hand Sketching the Nebulae in the 19th Century
book oF The monTh
books APRIL 111
skyatnightmagazine.com 2014
Wizards, Aliens and Starships Charles l adler Princeton £19.95 PB
Fans of science-fction
and fantasy tales
usually realise that
they need to suspend
belief and allow
some poetic licence
so that a story may
be told. While
a few authors
try hard to keep
their narratives
within the bounds of scientifc possibility,
others seem to make up new laws of
physics as they go along.
Wizards, Aliens and Starships looks
at many of the common concepts and
plot devices that are used in science
fction and examines the actual science
behind them. There’s a hefty chunk
dealing with the fantasy world of Harry
Potter to get past, but from there on
the book concerns itself with topics
of greater interest to astronomers and
space fans. How easy is it really to travel
vast distances in space, for instance?
What propulsion systems could be used?
What are the practicalities of founding
colonies and terraforming planets?
Will we ever travel faster than light?
What are the chances of fnding and
communicating with ET?
These are just a few of the range of
topics examined by author and professor
of Physics Charles Adler. He says this is
the book he would have wanted to read
as a 15-year-old boy, but offers a word of
warning: that readers should have some
knowledge of algebra and calculus; and
indeed there are many formulae and
equations scattered throughout the
book. Despite this, the writing style is
light and will give sci-f fans a rewarding
and thought-provoking read.
★★★★★
PaUl SUThErlaND is a space writer and journalist
reader price £14.95, subscriber price £13.95 P&P £1.99 Code: S0414/1
Omar W Nasim Chicago £31.50 hB
As befts its subject
matter, Observing by
Hand looks beautiful.
It deals with the
tricky, rather
under-researched
area of observational
astronomy, that
place between
observation and publication. Author Omar
Nasim uses tools from art history as well
as a good understanding of astronomy to
explore this complicated relationship
between art and science; between the eye,
the mind and the hand; between what is
observed and the image produced.
Today astronomy is intertwined with
photography. For a signifcant part of the
19th century, images were produced by hand,
requiring artistic skill, an understanding
of the heavens and an ability to record
detail accurately and quickly. The style of
writing refects the content, being careful
and meticulous, just as the observers were
who produced the images discussed.
Each chapter focuses on different
astronomers and how their approach to
drawing nebulae adds to the bigger story.
Through the work of Lord Rosse and his
assistants John Herschel, EP Mason, William
Lassell and Wilhelm Tempel, we see the
range of techniques used, and the factors
that shaped them. In doing so, Nasim
shows us the role theory played in shaping
what each astronomer saw, the skill
involved in ‘translating’ that onto paper,
and the fuidity of the border between art
and science. For anyone with an interest
and appreciation of the beauty of nebulae,
this is a book that will leave you thinking.
★★★★★
Dr EmIlY WINTErBUrN is a writer and visiting fellow at the University of Leeds
reader price £27.99, subscriber price £26.99 P&P £1.99 Code: S0414/4
John Bromley-Davenport Bene Factum Publishing£20 hB
Sir Bernard lovell was one of the most eminent British scientists of the past hundred years. a pioneer of radar techniques, originator of Jodrell Bank
Observatory and a popular orator of the physical sciences, his legacy is immense.
This biography by family friend John Bromley-Davenport, coming little more than a year after lovell’s death, is an insightful and detailed account of the astronomer’s life. Using carefully researched original documents, and peppered with personal anecdotes from lovell himself, Bromley-Davenport gives a fascinating profle of the man, his science, his beliefs, and his trials and tribulations.
although many of the basic details of lovell’s life are available elsewhere, this offering digs a little deeper into some of the major events of his life. The account of lovell’s wartime radar development is excellent, flling in hitherto unpublished details. The stresses and strains during the design and construction of the 76m radio telescope at Jodrell Bank that bears lovell’s name are ably portrayed. lovell’s involvement with certain secretive aspects of the Cold War are well known, but this account contains new facts based on recently released offcial records.
The assertion that lovell was duped by a committed marxist into believing he was an undercover government agent seems both incongruous and speculative. So too is the inference that lovell himself was a spy. Nevertheless, this biography is a fascinating and scholarly read.★★★★★
Dr alaSTaIr GUNN is a radio astronomer at Jodrell Bank Observatory in Cheshire
reader price £18.99, subscriber price £17.99 P&P £1.99 Code: S0414/3
Space Has No FrontierThe Terrestrial Life and Times of Sir Bernard Lovell
Observing by Hand Sketching the Nebulae in the 19th Century
book oF The monTh
1
2
4
skyatnightmagazine.com 2014
Elizabeth Pearson rounds up the latest astronomical accessories
Gear112 GEAR APRIL
5
63
1 Orion Newtonian Visual Centering Device
Price £139 • Supplier SCS Astro0800 0181544 • www.scsastro.co.uk
Designed for use with Newtonian refectors, this device allows you to centre your imaging target visually through its built-in eyepiece, rather than your camera’s screen or software.
2 Baader Classic Q-Eyepiece SetPrice £215 • Supplier The Widescreen Centre 020 7935 2580 • www.widescreen-centre.co.uk
The set includes four eyepieces, ranging from 6mm to 32mm, as well Baader’s Q-Turret, which slots into a telescope and allows you to switch between all four with ease. The set comes with a 2.25x Barlow lens.
3 Lacerta Newtonian Carry CasePrice From £72 • Supplier 365 Astronomy020 3384 5187 • www.365astronomy.com
Designed to transport and store Newtonian telescopes, this padded case helps keep your kit safe. Available in various sizes.
4 Celestron 9x50 Illuminated Right Angle Correct Image Finderscope
Price £112.99 • Supplier Harrison Telescopes01932 703605 • www.harrisontelescopes.co.uk
This fnderscope uses a dual crosshair, so you can centre objects without obscuring them. Its right-angled orientation makes it easy to use even when your scope is pointing at the zenith.
5 SmarTouch Chunky Knit Touchscreen GlovesPrice £15 • Supplier Totes01277 636802 • www.totes.co.uk
Conductive material in the fngertips promises to let you to carry on using touchscreen devices during cold observing sessions without the need to take your gloves off – smart indeed.
6 Lego Curiosity RoverPrice £24.99 • Supplier Lego00 800 5346 1111 • www.lego.com
Just like the real Curiosity rover, this Lego replica is capable of tackling a variety of terrains thanks to its rocker-bogie suspension system.
1
2
4
skyatnightmagazine.com 2014
Elizabeth Pearson rounds up the latest astronomical accessories
Gear112 GEAR APRIL
5
63
1 Orion Newtonian Visual Centering Device
Price £139 • Supplier SCS Astro0800 0181544 • www.scsastro.co.uk
Designed for use with Newtonian refectors, this device allows you to centre your imaging target visually through its built-in eyepiece, rather than your camera’s screen or software.
2 Baader Classic Q-Eyepiece SetPrice £215 • Supplier The Widescreen Centre 020 7935 2580 • www.widescreen-centre.co.uk
The set includes four eyepieces, ranging from 6mm to 32mm, as well Baader’s Q-Turret, which slots into a telescope and allows you to switch between all four with ease. The set comes with a 2.25x Barlow lens.
3 Lacerta Newtonian Carry CasePrice From £72 • Supplier 365 Astronomy020 3384 5187 • www.365astronomy.com
Designed to transport and store Newtonian telescopes, this padded case helps keep your kit safe. Available in various sizes.
4 Celestron 9x50 Illuminated Right Angle Correct Image Finderscope
Price £112.99 • Supplier Harrison Telescopes01932 703605 • www.harrisontelescopes.co.uk
This fnderscope uses a dual crosshair, so you can centre objects without obscuring them. Its right-angled orientation makes it easy to use even when your scope is pointing at the zenith.
5 SmarTouch Chunky Knit Touchscreen GlovesPrice £15 • Supplier Totes01277 636802 • www.totes.co.uk
Conductive material in the fngertips promises to let you to carry on using touchscreen devices during cold observing sessions without the need to take your gloves off – smart indeed.
6 Lego Curiosity RoverPrice £24.99 • Supplier Lego00 800 5346 1111 • www.lego.com
Just like the real Curiosity rover, this Lego replica is capable of tackling a variety of terrains thanks to its rocker-bogie suspension system.
What is life like on the ISS?
When you, a terrestrial human being,
go into space, you are faced with
the fact you are in a new
environment. You’re
there to work, and you want to work,
but frst of all you need to adapt
yourself. You fnd yourself
in a new place where there is
no gravity, and you have to
learn everything from
scratch. You need to
become an
extraterrestrial person.
It can be extremely
frustrating, but it is
also very nice, a bit
like being a little kid
discovering new things.
Most days followed the
same routine. At 6am you
wake up, have breakfast,
clean up and do whatever you
need to be ready to start work
at 7.30am.
We spent about eight hours doing
scheduled work. If we had a shuttle
arriving or a space walk to complete there
would be a lot to do to prepare, but most of that
time we were taking care of the station or carrying
out scientifc experiments.
A lot of hard workRunning experiments could be psychologically
taxing. We had to train for so many things that we
might have learnt how to carry out a particular
experiment a year beforehand. A couple of times
I went to do something and I had no idea I had
even trained for that experiment. Some were very
repetitive and I was always sleep deprived, so
sometimes I fell asleep! The scientists were
measuring my response time in milliseconds, but
I was napping. When that happened, I’d feel stupid.
One thing that helped was doing exercise – I could
switch off and think about other things. It is very
important to keep your body up to par and lower
the negative effects of microgravity, but exercising
was also very relaxing. Two hours every day were
spent on physical ftness. There is a special treadmill
as well as a machine called the Advanced Resistive
Exercise Device, which lets you do weightlifting in
About PAoLo NESPoLI
Paolo Nespoli served as a fight engineer aboard the ISS as part of Expeditions 26 and 27. He frst travelled to space aboard Space Shuttle Discovery in 2007.
space – a place where there is no weight!
At 8pm we usually had a debriefng where we
could talk about what happened during the
day and get feedback. After that we had
an hour and a half before we went to
sleep at 10pm, and could do
whatever we wanted.
I spent most of my time
going through emails and
talking with my family.
The International Space
Station is a confned,
isolated place and I was
grateful that there was
a way to communicate.
Ground control realises
that you are a human
being, not a machine,
and they come up with all
sorts of tricks to make it
more bearable. One of them
is to make sure each
of the astronauts has their own
phone. You need to pay attention
and check the availability of the
satellite it transmits through, but once
you learn how to use it it’s just like any other
phone. I would call people to say hello and
I talked to my wife every day to let her know what
was going on up there.
One of things I would do every day was go
into the cupola, a room with 360° views out into
space, and just look at Earth as we passed by.
I took something like 26,000 pictures while I was
in space. At frst it’s not easy; in the beginning
Earth seen from space is just this blue ball. But
as you become an extraterrestrial person, you
develop this eye. You can just glimpse down
and you know where you are.
I hope this experience is something that
many people will be able to do in the future.
You learn a lot about yourself, about other
people and about Earth. Seeing our planet
from up there gives you a perspective and
understanding that is very different from
any you can get from the ground – I wish everybody
could share that. Now that I’m back down on
the planet, though, I like to say that I am still
the same guy that grew up in a small town in
the middle of nowhere.
114 EXPERT inTERviEw APRIL
na
sa
/e
sa
skyatnightmagazine.com 2014
WHAT I REALLY WANT TO KNOW IS…
ESA astronaut Paolo Nespoli served as a fight engineer aboard the ISS from December 2010 to May 2011interviewed by eLiZAbetH PeArSOn
Nepsoli, right, was a prolifc photographer, taking 26,000 images
S
What is life like on the ISS?
When you, a terrestrial human being,
go into space, you are faced with
the fact you are in a new
environment. You’re
there to work, and you want to work,
but frst of all you need to adapt
yourself. You fnd yourself
in a new place where there is
no gravity, and you have to
learn everything from
scratch. You need to
become an
extraterrestrial person.
It can be extremely
frustrating, but it is
also very nice, a bit
like being a little kid
discovering new things.
Most days followed the
same routine. At 6am you
wake up, have breakfast,
clean up and do whatever you
need to be ready to start work
at 7.30am.
We spent about eight hours doing
scheduled work. If we had a shuttle
arriving or a space walk to complete there
would be a lot to do to prepare, but most of that
time we were taking care of the station or carrying
out scientifc experiments.
A lot of hard workRunning experiments could be psychologically
taxing. We had to train for so many things that we
might have learnt how to carry out a particular
experiment a year beforehand. A couple of times
I went to do something and I had no idea I had
even trained for that experiment. Some were very
repetitive and I was always sleep deprived, so
sometimes I fell asleep! The scientists were
measuring my response time in milliseconds, but
I was napping. When that happened, I’d feel stupid.
One thing that helped was doing exercise – I could
switch off and think about other things. It is very
important to keep your body up to par and lower
the negative effects of microgravity, but exercising
was also very relaxing. Two hours every day were
spent on physical ftness. There is a special treadmill
as well as a machine called the Advanced Resistive
Exercise Device, which lets you do weightlifting in
About PAoLo NESPoLI
Paolo Nespoli served as a fight engineer aboard the ISS as part of Expeditions 26 and 27. He frst travelled to space aboard Space Shuttle Discovery in 2007.
space – a place where there is no weight!
At 8pm we usually had a debriefng where we
could talk about what happened during the
day and get feedback. After that we had
an hour and a half before we went to
sleep at 10pm, and could do
whatever we wanted.
I spent most of my time
going through emails and
talking with my family.
The International Space
Station is a confned,
isolated place and I was
grateful that there was
a way to communicate.
Ground control realises
that you are a human
being, not a machine,
and they come up with all
sorts of tricks to make it
more bearable. One of them
is to make sure each
of the astronauts has their own
phone. You need to pay attention
and check the availability of the
satellite it transmits through, but once
you learn how to use it it’s just like any other
phone. I would call people to say hello and
I talked to my wife every day to let her know what
was going on up there.
One of things I would do every day was go
into the cupola, a room with 360° views out into
space, and just look at Earth as we passed by.
I took something like 26,000 pictures while I was
in space. At frst it’s not easy; in the beginning
Earth seen from space is just this blue ball. But
as you become an extraterrestrial person, you
develop this eye. You can just glimpse down
and you know where you are.
I hope this experience is something that
many people will be able to do in the future.
You learn a lot about yourself, about other
people and about Earth. Seeing our planet
from up there gives you a perspective and
understanding that is very different from
any you can get from the ground – I wish everybody
could share that. Now that I’m back down on
the planet, though, I like to say that I am still
the same guy that grew up in a small town in
the middle of nowhere.
114 EXPERT inTERviEw APRILn
as
a/e
sa
skyatnightmagazine.com 2014
WHAT I REALLY WANT TO KNOW IS…
ESA astronaut Paolo Nespoli served as a fight engineer aboard the ISS from December 2010 to May 2011interviewed by eLiZAbetH PeArSOn
Nepsoli, right, was a prolifc photographer, taking 26,000 images
S
skyatnightmagazine.com 2014
StarS and conStellationS
Leo is one of the few constellations
that looks like its namesake – but only
from the northern hemisphere. From down
under the Lion sits low in the north, but upside
down. Its head and shoulders are referred to
as the Sickle, with its top member Leo’s
brightest star, mag. +1.4 Regulus (Alpha (α)
Leonis). To the east lie its hindquarters,
consisting of a conspicuous triangle of stars.
This group’s brightest star is mag. +2.1
Denebola (Beta (β) Leonis): its name is short
for an Arabic phrase meaning ‘tail of the Lion’.
Teapot
TELESCO
SCORPIUS
SERPENS C
APU
TCO
RON
A BOREALIS
SERPENS CAUDA
OPH
IUC
HU
S
IND
SCUTUM
SAG
ITTARIU
S
CORONA
AUSTRALIS
HERC
ULES
αγδ
βγ
α
α
β
γ
γβ
α
δ
α
γ
δ
α
α
γδ
α
β
γ α
β δ
M16
M17
M20
M8
M12
M10
M19 M
62
M28
M22
M7
M6
M23
M25
Peacock
20th
NORTHEAST
EA
ST
SOUTHEAST
> 1 April 00:00 > 15 April 23:00 > 30 April 22:00
WHen to USe tHiS cHartThe chart accurately matches the sky on the dates and times shown. The sky is different at other times as stars crossing it set four minutes earlier each night. We’ve drawn the chart for latitude –35° south.
SoUtHern HeMiSPHere in aPril With Glenn Dawes
aPril HigHligHtS
A total lunar eclipse will be visible from
eastern Australia on 15 April. Mid-
eclipse is around moonrise in the evening
twilight: a good time to observe would be just
before totality ends at 18:24 EST. From central
Australia totality ends before moonrise, with
Western Australia missing all of the eclipse.
The afternoon of 29 April brings an annular
eclipse of the Sun with partial phases visible
across Australia. Maximum eclipse is
around 17:00 EST from the eastern states
and 15:00 EST from Western Australia.
Mars transits the meridian around
midnight and is visible the entire night.
Being at opposition, it reaches its brightest
(mag. –1.5) and maximum angular size
(15.2 arcseconds) during the month. Brilliant
Jupiter is in the northwest evening sky,
setting around 23:00 EST. The evenings also
offer Saturn, which arrives just after twilight
and is due north in the early morning. Venus
dominates the morning sky, rising around
3:00 EST, with Mercury briefy visible low in
the eastern dawn sky for the frst week of April.
tHe PlanetS
Autumn is a great time to observe
galaxies, one particularly remarkable
collection being Markarian’s Chain:
seven galaxies arranged in an
arc 1.5° long and visible in
6-inch scopes. The western
end is marked by mag.
+9.1 elliptical galaxy M84
(RA 12h 25.0m, dec. +12°
53’), pictured. It has a
3-arcminute circular core,
brighter but smaller than the
next member 16 arcminutes east,
M86. Journeying another 22 arcminutes
takes you to galaxy pair NGC 4435/4438.
The chain continues northeast
with the fainter NGC 4461,
NGC 4473 and NGC 4477.
Open cluster Melotte
111 (RA 12h 25.1m,
dec. +26° 06’) in Coma
Berenices is best seen with
binoculars. This scattered
group of 5th- to 8th-magnitude
stars is around 2° in diameter.
deeP-Sky objectS
NO
AO
/AU
RA
/NSF
GALAXY
OPEN CLUSTER
GLOBULAR
CLUSTER
PLANETARY
NEBULA
DIFFUSE
NEBULOSITY
DOUBLE STAR
VARIABLE STAR
COMET TRACK
ASTEROID
TRACK
METEOR
RADIANT
QUASAR
STAR
BRIGHTNESS:
MAG. 0
& BRIGHTER
MAG. +1
MAG. +2
MAG. +3
MAG. +4
& FAINTERPLANET
cHart key
skyatnightmagazine.com 2014
StarS and conStellationS
Leo is one of the few constellations
that looks like its namesake – but only
from the northern hemisphere. From down
under the Lion sits low in the north, but upside
down. Its head and shoulders are referred to
as the Sickle, with its top member Leo’s
brightest star, mag. +1.4 Regulus (Alpha (α)
Leonis). To the east lie its hindquarters,
consisting of a conspicuous triangle of stars.
This group’s brightest star is mag. +2.1
Denebola (Beta (β) Leonis): its name is short
for an Arabic phrase meaning ‘tail of the Lion’.
Teapot
TELESCO
SCORPIUS
SERPENS C
APU
TCO
RON
A BOREALIS
SERPENS CAUDA
OPH
IUC
HU
S
IND
SCUTUM
SAG
ITTARIU
S
CORONA
AUSTRALIS
HERC
ULES
αγδ
βγ
α
α
β
γ
γβ
α
δ
α
γ
δ
α
α
γδ
α
β
γ α
β δ
M16
M17
M20
M8
M12
M10
M19 M
62
M28
M22
M7
M6
M23
M25
Peacock
20th
NORTHEAST
EA
ST
SOUTHEAST
> 1 April 00:00 > 15 April 23:00 > 30 April 22:00
WHen to USe tHiS cHartThe chart accurately matches the sky on the dates and times shown. The sky is different at other times as stars crossing it set four minutes earlier each night. We’ve drawn the chart for latitude –35° south.
SoUtHern HeMiSPHere in aPril With Glenn Dawes
aPril HigHligHtS
A total lunar eclipse will be visible from
eastern Australia on 15 April. Mid-
eclipse is around moonrise in the evening
twilight: a good time to observe would be just
before totality ends at 18:24 EST. From central
Australia totality ends before moonrise, with
Western Australia missing all of the eclipse.
The afternoon of 29 April brings an annular
eclipse of the Sun with partial phases visible
across Australia. Maximum eclipse is
around 17:00 EST from the eastern states
and 15:00 EST from Western Australia.
Mars transits the meridian around
midnight and is visible the entire night.
Being at opposition, it reaches its brightest
(mag. –1.5) and maximum angular size
(15.2 arcseconds) during the month. Brilliant
Jupiter is in the northwest evening sky,
setting around 23:00 EST. The evenings also
offer Saturn, which arrives just after twilight
and is due north in the early morning. Venus
dominates the morning sky, rising around
3:00 EST, with Mercury briefy visible low in
the eastern dawn sky for the frst week of April.
tHe PlanetS
Autumn is a great time to observe
galaxies, one particularly remarkable
collection being Markarian’s Chain:
seven galaxies arranged in an
arc 1.5° long and visible in
6-inch scopes. The western
end is marked by mag.
+9.1 elliptical galaxy M84
(RA 12h 25.0m, dec. +12°
53’), pictured. It has a
3-arcminute circular core,
brighter but smaller than the
next member 16 arcminutes east,
M86. Journeying another 22 arcminutes
takes you to galaxy pair NGC 4435/4438.
The chain continues northeast
with the fainter NGC 4461,
NGC 4473 and NGC 4477.
Open cluster Melotte
111 (RA 12h 25.1m,
dec. +26° 06’) in Coma
Berenices is best seen with
binoculars. This scattered
group of 5th- to 8th-magnitude
stars is around 2° in diameter.
deeP-Sky objectS
NO
AO
/AU
RA
/NSF
GALAXY
OPEN CLUSTER
GLOBULAR
CLUSTER
PLANETARY
NEBULA
DIFFUSE
NEBULOSITY
DOUBLE STAR
VARIABLE STAR
COMET TRACK
ASTEROID
TRACK
METEOR
RADIANT
QUASAR
STAR
BRIGHTNESS:
MAG. 0
& BRIGHTER
MAG. +1
MAG. +2
MAG. +3
MAG. +4
& FAINTERPLANET
cHart key
SoUtHern HeMiSPHere
skyatnightmagazine.com 2014
Celestial Equator
Ecliptic
Sickle
Kite
Winter Triangle
FalseCross
CANIS MIN
OR
MO
NO
CERO
SCA
NIS
MAJ
OR
OCTANS
TUCANA
HYDRUSRETICULUM
DORADO
PICTOR
COLUMBA
PUPP
IS
CARINA
VELA
VOLANS
APUS
PAVO
TRIANGULU
M
AUSTRA
LE
CIRCINUS
MUSCA
CENTAURUS
CRUX
CHAMAELEON
ARA
PYXI
S
MEN
SA
CA
NC
ER
HYDRA
LEO
South Celestial Pole
CORVUS
LYNX
CRATER
VIRGO
LUPUS
URSAMAJOR
LEO MINORCOMA
BERENICES
NO
RMA
AN
TLIA
LIBRA
BOÖTES CANES VENATICI
ELESCOPIUM
SCORPIUS
SERP
INDUS
RONARALIS
Markarian’s
Chain
Melotte 111
α
β
δγ
β
α
α
β
α
γβ
δ
α
β γ
α
β
γ
αδ
β
δ
α
γ
α
β
δ
β
γ
α
δ
δ γ
αβγ
β
α
δ
α
β
δ
γ
β
δ
α
β
δγ
β
α
α
δβ
α
γ
δ
β
α
δ γ
γ
δ
β βα
δ
γ
α
γβ
δ
α
β
δ
γ
α
γ
βδ
αβ
γ δ
δγ
β α
α
δ
γ
β
γ
β
α
δ
α
βα
β
γ δ
α
γδβ
γδ
β
α
β γ
αδ
δ
β
α
γ
β
δ
β
α
δ
α
γβ
δ
αβ
δ
γ
δ
β
γ
α
αγ
β
R
R
υ
εb
ι
Saturn
Mars 30th1st
Tarantula Nebula
M5
M
M4
ω C
en
47 Tuc
M3
M44
M48
M47
M41
Jewe
l Box
Coal Sack
NG
C 3195
M93
LMC
SMC
Cen A
M83
M104Leo Triplet
M60 M87
M86
M64
M94M63
M51 M106
M84
Ghost of Jupiter
Rigel Kent
Acherna
r
Canopus
Sirius
Acr
ux
Procyon
Alm
ach
Alphard
Hadar
Regulus
Spica
Arcturus
Cor Caroli
Antares
Peacock Star
Den
ebol
a
8th
11th
14th
17th
NORTH
SOUTH
SOUTH
WES
T
WES
T
N
ORTHW
EST
SoUtHern HeMiSPHere
skyatnightmagazine.com 2014
Celestial Equator
Ecliptic
Sickle
Kite
Winter Triangle
FalseCross
CANIS MIN
OR
MO
NO
CERO
SCA
NIS
MAJ
OR
OCTANS
TUCANA
HYDRUSRETICULUM
DORADO
PICTOR
COLUMBA
PUPP
IS
CARINA
VELA
VOLANS
APUS
PAVO
TRIANGULU
M
AUSTRA
LE
CIRCINUS
MUSCA
CENTAURUS
CRUX
CHAMAELEON
ARA
PYXI
S
MEN
SA
CA
NC
ER
HYDRA
LEO
South Celestial Pole
CORVUS
LYNX
CRATER
VIRGO
LUPUS
URSAMAJOR
LEO MINORCOMA
BERENICES
NO
RMA
AN
TLIA
LIBRA
BOÖTES CANES VENATICI
ELESCOPIUMSCO
RPIUS
SERP
INDUS
RONARALIS
Markarian’s
Chain
Melotte 111
α
β
δγ
β
α
α
β
α
γβ
δ
α
β γ
α
β
γ
αδ
β
δ
α
γ
α
β
δ
β
γ
α
δ
δ γ
αβγ
β
α
δ
α
β
δ
γ
β
δα
β
δγ
β
α
α
δβ
α
γ
δ
β
α
δ γ
γ
δ
β βα
δ
γ
α
γβ
δ
α
β
δ
γ
α
γ
βδ
αβ
γ δ
δγ
β α
α
δ
γ
β
γ
β
α
δ
α
βα
β
γ δ
α
γδβ
γδ
β
α
β γ
αδ
δ
β
α
γ
β
δ
β
α
δ
α
γβ
δ
αβ
δ
γ
δ
β
γ
α
αγ
β
R
R
υ
εb
ι
Saturn
Mars 30th1st
Tarantula Nebula
M5
M
M4
ω C
en
47 Tuc
M3
M44
M48
M47
M41
Jewe
l Box
Coal Sack
NG
C 3195
M93
LMC
SMC
Cen A
M83
M104
Leo Triplet
M60 M87
M86
M64
M94M63
M51 M106
M84
Ghost of Jupiter
Rigel Kent
Acherna
r
Canopus
Sirius
Acr
ux
Procyon
Alm
ach
Alphard
Hadar
Regulus
Spica
Arcturus
Cor Caroli
Antares
Peacock Star
Den
ebol
a
8th
11th
14th
17th
NORTH
SOUTH
SOUTH
WES
T
WES
T
N
ORTHW
EST
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