mac january 2012 magazine

Above: Orion includes the prominent asterism known as the 'belt' of Orion: three bright stars in a row. Surrounding the belt at roughly similar distances are four bright stars, which are considered to represent the outline of the hunter's body. Descending from the 'belt' is a smaller line of three stars (one of which is in fact not a star but the Orion Nebula), known as the hunter's 'sword'. Right: The Crab Nebula (M1) in the constellation Taurus.

satellites and details on the planet’s surface with the rings out of the picture. Venus is visible in the early morn ing hours b laz ing at magnitude -4.1. Venus shows phases through the telescope similar to the moons phases. Watch Venus weekly as it grows in apparent size and the phases shift.

Wel l , that 's about i t for January's picks although with a good star map there are tons of wonderful sights to be had on cold winter nights. Clear skies and good hunting!

out to where the V seems to end at another fairly bright star (Zeta Tauri). Go up toward the other side of the V about a fifth of the distance toward the other star (El Nath) and you should see a dim "fuzz." Dark skies are needed for this one though.

Planets J u p i t e r c o n t i n u e s t o b e available in the early evening with Saturn following Jupiter across the sky. Saturn can be located in Leo this month. With the planet’s ring plane almost edge on, this is not a good time to try and observe the rings. It is however a good time to try and observe the smaller

Alnitak

Crab Nebula

them easily with my 4.5" reflector. In the same telescopic view, more or less attached to M42 is M43, a small patch of nebulosity separate from M42.

We also have a nice multiple star system in Orion, Sigma Orionis. To find this system, use the eastern most star of Orion's belt (Alnitak). Just below Alnitak is a dimmer star, this is Sigma Orionis. Focus in on this star at high power, and it should split into what looks like 3 separate stars. In most small telescopes, Sigma Orionis will look like a triple star. Also in the same field of view is another triple star system known as Struve 761.

Also in Orion are many double stars. Alnitak is a tough double to split with a separation of only 2.4 arc-seconds. Mintaka (the star on the right side of the belt). The companion is somewhat dim glowing at only 7th magnitude.

Also up for January is a super-nova remnant (SNR), the Crab Nebula. This is the remains of a star that exploded in 1054AD which makes this a youngster in astronomical terms. Up and to the right of Orion there is a "V" shaped grouping of stars (the head of Taurus the Bull). The Hyades are part of this V as well. A very bright orange-red star (Aldeberan) sits as the third star in the line of the V. follow this line

For the naked eye in January, we have another meteor shower to look forward to. The Quadrantids generally begin on January 1st and end on January 7th, with the maximum occurring this year on the evening of the 4th. The shower coincides with the moon so moonlight will not interfere with observing at any hour of the night. Observers in the Northern Hemisphere can see around 60 meteors per hour or more at m a x i m u m . L o o k f o r meteors radiating from the constellation Bootes near the plough/big dipper.

Telescope Targets Many of Autumn's targets are still available early in the evening. See November's and December's picks for these.

For January, Or ion reigns supreme in the sky. One of the brightest and best nebula is the Great Orion Nebula (M42). This is also one of the easiest (if not the easiest) deep sky targets to locate. Hanging from the belt of Orion (3 stars in a row of equal magnitude) are 3 more stars (his sword). The second "star" of these is the nebula. Folks with good eyes can make out colour (typically green) at higher powers. Push the power up and look for the 4 stars in the centre that provide the luminosity for this nebula. These are known as the trapezium and I have seen

www.midlandsastronomy.com

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Midlands Astronomy Club Magazine

Issue 30- January, 2012

Latest Astronomy and Space News

Kids Astronomy

Quizzes and Games

Monthly Sky Guide

Internet Highlights

Sky Guide - Beginner’s targets for January

Club Notes

Club Observing:

Remember the next club meets every first Friday of the month for our observing sessions held in the MAC grounds. If you wish

to be informed of these sessions please email your name and mobile number to [email protected] who will con-

firm if the session is going ahead (depending on weather).

MAC is a proud member of


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Midlands Astronomy Club Magazine Midlands Astronomy Club Magazine

c o n t e n t sc o n t e n t sc o n t e n t sc o n t e n t s Latest Astronomy and Space News NASA's Kepler finds two Earth-size Planets around sunlike Star ......................................................................... 3

First ever Pulsar found in a Supernova Remnant ................... 3

Earth’s other Moons ............................................................ 4

Have complex molecules been found on Pluto’s surface? ....... 4

Echoes from η Carinae’s great eruption ................................ 5

Ten tips for using a new telescope ....................................... 6

Top Astronomy events coming up in 2012 ............................ 7

Is Jupiter’s core liquefying? .................................................. 8

Asteroid crash may explain Mercury's strange spin ................ 8

Bucket List Object #3: A Bright Comet ................................. 9

Kids Section Kids Korner ....................................................................... 10

Quizzes and Games Exercise your brain ............................................................ 11

Monthly Sky Guide Beginners sky guide for this month .................................... 12

Internet Highlights Special content only available with the online version of the magazine ................................................................ 13

Front cover image: Two galaxies colliding galaxies in Corvus but the stars that compose them usually do not

crash into each other. That's because galaxies are mostly empty space and,

however bright, stars only take up only a small amount of that space.

During the slow, hundred million year

collision, one galaxy can still rip the other apart gravitationally, and dust and gas

common to both galaxies does collide. In this clash of the titans, dark dust pillars mark

massive molecular clouds are being compressed during the galactic encounter, causing the rapid birth of millions of stars, some of which are gravitationally bound

together in massive star clusters.

Credit & Copyright: INASA, ESA & B. Whitmore (STScI) et al.

MAC meets on the first Tuesday of

the month in the Presbyterian Hall, High Street, Tullamore from 8pm.

All are welcome to attend. It also holds infrequent Observing

Nights at its Observing Site in

Clonminch, or at a member’s house (weather permitting) on the first

Friday of every month..

You can see more about the club and its events on


or contact the club via e-mail at [email protected]

Meetings are informal and are aimed at a level to suit all ages.

Exercise your brainExercise your brainExercise your brainExercise your brain 1. What is a bright streak

of light seen in the sky?

� Meteorite

� Asteroid

� Meteroid

� Meteor

2. Light travels at 186,282 miles per ___________

� hour

� minute

� second

� year

3. What is a depression on

a terrestrial planet or

satellite called?

� Hill

� Crater

� Mountain

� Ridge

4. The uppermost region

of the Sun is called the?

� Photosphere

� Ionosphere

� Chromosphere

� Corona

5. A medium sized icy solar system object is called

a?

� Asteroid

� Planet

� Comet

� Star

1

9 3 4 8

6 7 5 2 1

1 3 7 8

1 5 2 4

4 7 6 5

7 5 6 1 4

1 2 4 9

9

SUDOKU

Check your answers

Answer 1: The correct answer was Mete-or. A meteroid is the object before it

encounters the Earth's atmosphere. A meteorite is the object that survives the

journey through the atmosphere to im-pact on the Earth. Asteroids are objects made of rock and iron and most are in the

main asteroid belt between Jupiter and Mars.

Answer 2: The correct answer was second or about 300,000 kilometers a second.

The nearest star system to our Sun is some 4.3 light years away. This is easier to say than 25 trillion miles away.

Answer 3: The correct answer was Crater. Craters are mostly oval or round in shape.

They result when an asteroid or comet impacts a world.

Answer 4: The correct answer was Coro-na. The corona is what we see during a

total solar eclipse. The chromosphere is between the photosphere and the corona of the Sun. The ionosphere is the upper

part of a planet's atmosphere.

Answer 5: The correct answer was Comet.

Comets are mostly ice and rock with some dust and asteroids are mostly rock and

metal.

Answer 6: The correct answer was Bolide.

A fireball is a meteor that is brighter than -3 magnitude, almost as bright as the

planet Venus gets.

Answer 7: The correct answer was Magni-

tude. The magnitude system was actually invented by Hipparchus, an astronomer

that lived from 190 B.C. to 120 B.C.

Answer 8: The correct answer was a

parsec. A parsec is the distance from the Sun which results in a parallax of 1 se-cond of arc. One astronomical unit is the

mean distance between the Sun and the Earth. The nearest star is 1.3 parsecs

away (Proxima Centauri).

Answer 9: The correct answer was Plage.

These are bright regions seen in the Sun's chromosphere. Sunspots are "cooler" regions on the Sun. Prominences follow

the Sun's electromagnetic lines and flow back into the Sun. Flares are matter that

has been ejected from the Sun in a violent explosion, this matter does not return to the Sun but continues out into the solar

system.

Answer 10: The correct answer was

Retrograde. Triton (Neptune's satellite) is the largest satellite that is retrograde

around its planet. There are smaller satellites in the solar system that are also retrograde around their planet.

Confused???

Check your answers on this page.

6. What is a fireball that

produces a sonic boom called?

� meteorite

� No such object

� Bolide

� Comet

7. What is the brightness

scale of stars called?

� Magnitude

� Temperature

� Albedo

� Density

8. 3.26 light years is called?

� an astronomical Unit

� the distance to the

nearest star

� nothing

� a parsec

9. What is a bright region in the Sun called?

� Prominence

� Sunspot

� Plage

� Flare

10.What is the name for

an object that goes around another object

backwards called?

� Retrograde

� Upside down

� Prograde

� Normal


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smaller, rocky planets. This is a different structure from our solar system, where the rocky worlds are closer to the sun while the gas giants have more outlying orbits.

To find planets around sunlike stars, the Kepler spacecraft continually observes one section of sky within the constellations Cygnus and Lyra. In this field of view, Kepler detects changes in the brightnesses of individual stars, which may indicate the presence of planets transiting—or passing in front of—a star, as seen from Earth.

To date, the Kepler mission has identif ied more than 2,300 exoplanet candidates—worlds that are suspected of orbiting other stars but that need more observations to be confirmed.

Further observations will be needed

contrast, Earth's average surface temperature is 57.2ºF (14°C).

Still, this is the first confirmation of truly Earth-size planets by the Kepler team—a key goal of the overall mission. "December 2011 may be remembered as the first time humanity was able to discover an Earth-size planet in orbit around another star," lead author Francois Fressin said today during a NASA teleconference. The discovery "demonstrates for the first time that Earth-size planets exist around other stars, and that we are able to detect them."

Previously discovered exoplanets have all been considerably larger than Earth. Even the just announced Goldilocks world, Kepler-22b, was estimated to be 2.4 times Earth's radius and is thought to have a fairly low density, meaning it could have a thick atmosphere and a surface quite unlike Earth's.

A curious feature of the Kepler-20 system is that the other three known planets, which are Neptune-size worlds, orbit among the

The find comes on the heels of Kepler's first potentially Earthlike planet orbiting squarely within its star's water-friendly "Goldilocks zone"—the region that's not too hot and not too cold for liquid water to exist on a planet's surface.

Designated Kepler-20e and Kepler-20f, the two new planets are comparable in size to Earth and Venus: At 0.87 times the size of Earth, Kepler-20e is slightly smaller than Venus, while Kepler-20f is 1.03 times Earth's radius. But both new extraso lar p lanets—or exoplanets—orbit their star much too closely to be within the habitable zone.

In fact, the entire Kepler-20 system is believed to contain at least five planets all orbiting their star within a distance smaller than that between Mercury and the sun.

This orbital distance makes the planets very hot. For instance, Kepler-20e is estimated to have an average surface temperature of 1,400ºF (760ºC), while Kepler-20f is a "cooler" 800ºF (427ºC). By

Two new planets found orbiting a sunlike star are the first truly Earth-size worlds discovered by NASA's Kepler mission, scientists recently announced.


NASA's Kepler finds two Earth-size Planets around

sunlike Star

Kid’s�Korner�

Above: A size comparison of two new planets with Earth and Venus.

to find that "holy grail" of exoplanet discovery: an Earth-size world located within a sunlike star's habitable zone—and possibly even containing liquid water on its surface.

"What drives the Kepler team is cont inuing to f ind smaller exoplanets farther from their stars we need more data." But for that to happen, the Kepler mission will need more time—and that could require a mission extension. For now, the project is slated to end in November 2012.

Still, even with the current mission time line, "we are hoping to announce in the next two years the discovery of an Earth-size, habitable exoplanet."

www.universetoday.com

perspect ive, s ince i t was presumably formed in the same explosion that produced the supernova remnant. Assuming that it was born with rapid spin, it is a mystery why SXP 1062 has been able to slow down by so much, so

First ever Pulsar found in a Supernova Remnant

quickly. Work has already begun on theoretical models to understand the evolution of this unusual object.

The diffuse X-rays and optical shell are both evidence for the supernova remnant surrounding the pulsar. The optical data also displays spectacular formations of gas and dust in a star-forming region on the left side of the image. A comparison of the Chandra image with optical images shows that the pulsar has a hot, massive companion.

Astronomers are interested in SXP 1062 because the Chandra and XMM-Newton data show that it is rotating unusually slowly -- about once every 18 minutes. In contrast,

some pulsars are found to revolve multiple times per second, including most newly born pulsars. This relatively leisurely pace of SXP 1062 makes it one of the slowest rotating X-ray pulsars in the SMC.

In the image top of page X-rays from Chandra and XMM-Newton have been colored blue and optical data from the Cerro Tololo Inter-American Observatory in Chile are colored red and green. The pulsar, known as SXP 1062, is the bright white source located on the right-hand side of the image in the middle of the diffuse blue emission inside a red shell.

www.dailygalaxy.com

Two different teams of scientists have estimated that the supernova remnant around SXP 1062 is between 10,000 and 40,000 years old, as it appears in the image. This means that the pulsar is very young, from an astronomical

Data from NASA's Chandra X-ray Observatory and ESA's XMM-Newton have been combined to discover a young pulsar in the remains of a supernova located in the Small Magellanic Cloud, or SMC. This would be the first definite time a pulsar, a spinning, ultra-dense star, has been found in a supernova remnant in the SMC, a small satellite galaxy to the Milky Way.

Build your own rocket using paper and fizzing tablets! Watch it lift off. How high does your rocket go? Print this page for the instructions.

Suggestion: Find a grown-up to do this activity with you.

Materials:

• Paper, regular 8-1/2-

by 11-inch paper, such as computer printer paper or even notebook paper.

• Plastic 35-mm film canister (see

hints below)

• Cellophane tape

• Scissors

• Effervescing (fizzing) antacid

tablet (the kind used to settle an upset stomach)

• Paper towels

• Water

• Eye protection (like eye glass-

es, sun glasses, or safety glass-es)

Hints: Right kind of film canister - The film canister MUST be one with a cap that fits INSIDE the rim instead of over the outside of the rim. Sometimes photography shops have extras of these and will be happy to donate some for such a worthy cause.

Keep in mind: Just like with real rockets, the less your rocket weighs and the less air resistance (drag) it has, the higher it will go.

Making the Rocket: You must first decide how to cut your paper. You may cut it the short way or the long way to make the body of the rocket. There is no

one right way to make a paper rocket. Try a long, skinny rocket or a short, fat rocket. Try a sharp nosecone or a blunt nosecone. Try it with fins or without fins. Experiment!

Here's just one idea for how you might cut your whole rocket from one piece of paper:

Here are the basic steps: Young rocket engineer

1. Cut out all the pieces for your rocket.

2. Wrap and tape a tube of paper around the film canister. Hint: Tape the canister to the end of the paper before you start wrapping. Important! Place the lid end of the canister down.

3. Tape fins to your rocket body, if you want.

4. Roll the circle (with a wedge cut out) into a cone and tape it to the rocket's top.

Blasting Off 1. Put on your eye protection. 2. Turn the rocket upside down

and remove the canister's lid. 3. Fill the canister one-third full of

water. Now work quickly on the next steps!

4. D r o p o n e - h a l f o f a n effervescing antacid tablet into the canister.

5. Snap the lid on tight. 6. Stand your rocket on a launch

platform, such as your sidewalk or driveway.

7. Stand back and wait. Your rock-et will blast off!

Roll this long piece around the film canister for the rocket body

Tape canister to the edge of paper before you start rolling paper around canister.

For a nosecone, use a jar lid or something like that to trace the circle required.

Above: A finished rocket ready for lift-off.

Build a Bubble Powered Rocket!

http://www.marcsobservatory.com/default.html



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In late 2006, observers at the Catalina Sky Survey in Arizona found an object orbiting the Earth. At first, it looked like a spent rocket stage — it had a spectrum similar to the titanium white paint NASA uses on rocket stages that end up in heliocentric orbits. But closer inspection revealed that the object was a natural body. Called 2006 RH120, it was a tiny asteroid measuring just a few metres across but it still qualified as a natural satellite just like the Moon. By June 2007, it was gone. Less than a year after it arrived, it left Earth’s orbit in search of a new cosmic companion.

They found that the Earth-Moon system captures NEOs quite frequently. “At any given time, there should be at least one natural Earth satellite of 1-meter diameter orbiting the Earth,” the team said. These NEOs orbit the Earth for about ten months, enough time to make about three orbits, before leaving.

L u c k i l y , a n d v e r y interestingly, this discovery has implication well beyond academic applications.

Knowing that these small satellites come and go but that one is always present a r o u n d t h e E a r t h , astronomers can work on detecting them. With more complete information on these bodies, specifically their position around the Earth at a given time, NASA could send a crew out to investigate. A crew wouldn’t be able to land on something a few metres across, but they could certainly study it up close and gather samples.

Proposals for a manned mission to an asteroid have been floating around NASA for years. Now, astronauts won’t have to go all the

Now, astrophysicists at Cornell are suggesting that 2006 RH120 wasn’t an anomaly; a second temporary moon is actually the norm for our planet.

These temporary satellites are a result of the gravitational pull of Earth and the Moon. Both bodies pull on one another and also pull on anything else in nearby space. The most common objects that get pulled in by the Earth-Moon system’s gravity are near Earth objects (NEOs) — comets and asteroids are nudged by the outer planets and end up in orbits that

bring them into Earth’s neighbourhood.

The team from Cornell, astrophysicists Mikael G r a n v i k , J e r e m i e Vauba i l l on , R obe r t Jedicke, has modeled the way our Earth-Moon system captures these NEOs to understand how often we have additional moons and how long they stick around.

way out to an asteroid to learn about the Solar System’s early history. NASA can wait for an asteroid to come to us.

If the Cornell team is right and there is no shortage of second satellites around the Earth, the gains from such missions increases. The possible information about the solar system’s formation that we could obtain would be amazing, and amazingly cost-efficient.


dimmest performance in recorded history, though it's been reliably bright over the past millennia. This most famous of comets has a rich historical background that makes it rewarding to observe. Known since antiquity, the comet served as an omen over the centuries, and marked many historical events, including the Battle of Hastings in 1066, and the invasion of Europe by Genghis Khan in 1222.

The comet also gave Edmund Halley a chance to test Newton's newly discovered laws of gravitation, and determine that several historical comets were actually the same comet that returned every 76 years.

Halley predicted this comet's return in 1758, and he was correct. While he didn't live long enough to see it himself, his name remains associated with this

While a half-dozen comets come and go each year, most are too faint to see without optical aid. But a bright comet, with a swollen head brighter than Venus and a tail streaking a third of the way across the sky is a stunning and unnerving sight, one that should be seen by even the most casual stargazer. It's a sight you'll never forget, and it comes in at #3 on our Bucket List.

By cosmic standards, a comet doesn't amount to much. It's a tiny remnant of the formation of the solar system, a dusty ice ball a few kilometres across that floats unseen in the outer reaches of the solar system.

But from time to time, a passing star or giant molecular cloud gives an anonymous comet a little nudge, and it starts a long journey towards the inner solar system. If the timing and mechanics are right, such a comet may put on a spectacular show in the night sky.

On average, a bright and truly spectacular comet comes about once a decade. The last was Comet McNaught in 2007, a dazzling sight for southernhemisphere observers that (so far) is considered the “comet of the century”. Before that, there were the back-to-back appearances of Comet Hale-Bopp and Comet Hyukutake in 1997 and 1996. And before that, Comet West put on a lovely show in the pre-dawn skies in 1976. There have been other dazzlers, too, including three comets in the 19th century bright enough to see in the daytime sky, and a fourth that appeared early in 1910.

The return of Comet Halley was a dud in 1986. The comet gave its

periodic visitor. Halley's Comet is the brightest of the short-period comets that return to the inner solar system every few years or decades. But most bright comets have orbital periods measured in thousands of years. And some

bright comets visit just once, never to return.

Mos t b r igh t come ts a r r i ve unpredictably from the distant Oort Cloud. They're often discovered accidentally by amateur and professional astronomers with large telescopes and complex imaging equipment.

No photograph or experience can prepare you for the magnificent and ghastly sight of a bright comet in the night sky. When you see one, you understand why they caused such fear in more superstitious times. The apparent size of the coma, or head, of the comet can be larger than any other sight save the Moon or Sun. And the tail can display lovely fine structure and filaments that can change over the course of minutes and hours. No other celestial object matches its appearance.

The great Mark Twain was born during the return of Halley's Comet in 1835. In 1909, he predicted his life would end with the comet's return. “The Almighty has said, no doubt”, wrote Twain, “Now here are these two unaccountable freaks; they came in together, they must go out together”. Twain died in April, 1910, a day after Comet Halley made its closet approach to the Sun.

It's hard to arrange your life around a comet (as did Mark Twain), but a careful and leisurely examination of a bright comet is a delightful event in the life of any stargazer. When one comes along, make sure you see it, savour it, and cross it off your celestial bucket list.

www.oneminuteastronomer.com

New research suggests that a second temporary moon orbiting the Earth is actually the norm for our planet.

Earth’s other Moons Bucket List Object #3: A Bright Comet

Over the next several months, we present our totally subjective list of ten celestial sights to see before you die, or “kick the bucket”, as they say. We call it the “Bucket List for Backyard Stargazers”. Our list is targeted at the casual stargazer, with no special expertise or training or ambition other than to see some of the most beautiful, and in some cases, transient sights in nature. For some of these objects, you’ll need access to a pair of binoculars or a small telescope. Others require travel and good timing and luck. And for others, you need to simply look up. But all these sights are not that hard to see, once you know how and when and where to look for them. We’ll help you with that.

Left: Comet P1

McNaught, taken from

Victoria, Australia in 2007.

The findings come from the Hubble Space Telescope, using the new and highly sensitive Cosmic Origins Spectrograph which indicate that there is a strong ultraviolet-wavelength absorber on the surface. This absorbing material is thought to likely be complex hydrocarbons and/or nitriles.

Pluto’s surface is known to be coated with ices composed of methane, carbon monoxide and nitrogen. The putative molecules can be produced by sunlight or cosmic rays interacting with them.

Have complex molecules been found on Pluto’s surface?

“This is an exciting finding because complex Plutonian hydrocarbons and other molecules that could be responsible for the ultraviolet spectral features we found with Hubble may, among other things, be responsible for giving Pluto its ruddy colour,” said project leader Dr. Alan Stern.

The team also found evidence for surface changes in the ultraviolet spectrum, comparing current observations to those from the 1990s. The cause may be an increase in the pressure of Pluto’s

First there was the recent story about evidence for a possible subsurface ocean on Pluto, of all places. Now there is a new report regarding evidence for complex molecules on its surface, from scientists at Southwest Research Institute and Nebraska Wesleyan University. Little enigmatic Pluto is starting to get even more interesting…

t e n u o u s atmosphere or different terrain which i s be ing viewed at d i f f e r e n t times.

With all of the new d i s cover i es already being made about P luto, i t should be v e r y i n t e r e s t i ng when New Horizons gets there in 2 0 1 5 , providing us with the first close-up look of this fascinating little world.


Left: Artist's conception of New Horizons during its flyby of Pluto in 2015.

Above: Saturn's moons Rhea and Dione as seen by the Cassini spacecraft. Could this be a future view from Earth?

Above: Near Earth object Eros, the

type of object that could be a second


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The reflected light has its properties changed by the motion of the material off which it reflects. In particular, the light shows a no t ab le b l uesh i f t , t e l l i n g astronomers that the material itself is traveling 210 km/sec.

This observation fits with theoretical predictions of eruptions similar to the type η Carinae is thought to have undergone. However, the light echo has also highlighted some discrepancies be tween expec ta t i on and observation.

Light echoes have been made famous in recent years by the dramatic example of V838 Monocerotis. While V838 Mon looks like an expanding shell of gas, what is actually depicted is light reflecting off shells of gas and dust that was thrown off earlier in the star’s life.

The extra distance the light had to travel to strike the shell, before being reflected towards observers on Earth, means that the light arrives later. In the case of η Carinae, nearly 170 years later!

Typically, η Carinae’s eruption is classif ied as a “supernova impostor”. This title is fitting since the eruptions create a large change in the overall brightness. However, although these events may release 10% of the total energy of a typical supernova or more, the star remains intact.

The main model to explain such eruptions is that a sudden increase in the star’s energy output causes some of the outer layers to be blown off in an opaque wind. This shell of material is so thick, that it gives a large increase in the effective surface area from which light is emitted, thereby increasing the overall brightness.

However, for this to happen, mode l s p r ed i c t t h a t t h e temperature of the star prior to the eruption needs to be at least 7,000 K. Analysing the reflected light from the eruption places the temperature of η Carinae at the time of the eruption at a much lower 5,000 K. This would suggest that the favoured model for such events is incorrect and that another model, involving an energetic blast was (a mini-supernova), may be the true culprit, at least in η Carinae’s case.

Echoes from η Carinae’s great eruption During the mid 1800′s, the well known star η Carinae underwent an enormous eruption becoming for a time, the second brightest star in the sky. Although astronomers at the time did not yet have the technology to study one of the largest eruptions in recent history in depth, astronomers from the Space Telescope Science Institute recently discovered that light echoes are just now reaching us. This discovery allows astronomers to use modern instruments to study η Carinae as it was between 1838 and 1858 when it underwent its Great Eruption.

The core is composed of iron, rock and ice and weighs about ten times as much as Earth. That’s still small though, compared to the overall mass of Jupiter itself, which weighs as much as 318 Earths! The core is buried deep within the thick atmosphere of hydrogen and helium. Conditions there are brutal, with a temperature of about 16,000 kelvin – hotter than the surface of the Sun – and a pressure about 40 million times greater than the atmospheric pressure on Earth. The core is surrounded by a fluid of metallic hydrogen which results from the intense pressure deep down in the atmosphere. The bulk of Jupiter though is the atmosphere itself, hence why Jupiter (and

like at genesis. Did it have a substantial core at that time? If so, was it 10 Earth masses, 15, 5?”

The findings also mean that some exoplanets which are even larger and more massive than Jupiter, and thus likely even hotter at their cores, may no longer have any cores left at all. They would be indeed be gas giants in the most literal sense.

Saturn, Uranus and Neptune) are called gas giants.

One of the primary ingredients in the rock of the core is magnesium oxide (MgO). Planetary scientists wanted to see what would happen when it is subjected to the conditions found at the core; they found that it had a high solubility and started to dissolve. So if it is in a state of dissolution, then it was probably larger in the past than it is now and scientists would like to understand the process. According to David Stevenson of the C a l i f o r n i a I n s t i t u t e o f Technology, ”If we can do that, then we can make a very useful statement about what Jupiter was

Jupiter, the largest and most massive planet in our solar system, may be its own worst enemy. It turns out that its central core may in fact be self-destructing, gradually liquefying and dissolving over time. This implies it was previously larger than it is now, and may dissolve altogether at some point in the future. Will Jupiter eventually destroy itself completely? No, probably not, but it may lose its heart…

Is Jupiter’s core liquefying?


The conditions inside Jupiter’s core can’t be duplicated in labs yet, but the spacecraft Juno should provide much more data when it arrives at and starts orbiting Jupiter in 2016.


Yet this observation is somewhat at odds with observations made in the years following the eruption. As spectrography came into use, astronomers in 1870 visually noticed emission lines in the star’s spectrum which is more typical in hotter stars.

In 1890, η Carinae had a smaller eruption and a photographic spectrum put the temperature around 6,000 K. While this may not accurately reflect the case of the Great Eruption, it is still puzzling how the star’s temperature could change so quickly and may also indicate that the favoured model of the opaque-wind model is a better fit for later times or the smaller eruption, which would suggest two different mechanisms causing similar results in the same object on short timescales.

Either way, η Carinae is a marvellous object. The team has also identified several other areas in the shell surrounding the star which appear to be brightening and undergoing their own echoes which the team promises to continue to observe which would allow them to verify their findings.


Above: Eta Carinae (η Carinae or η Car) is a stellar system in the constellation Carina, about 7,500 to 8,000 light-years from the Sun.

When one body orbits another — say, a moon around a planet or a planet around a star — the orbiting body often spins. Our planet experiences day and night because it spins on its axis, regularly changing which side it exposes to the sun.

However, the gravitational pull that orbiting moons and planets experience slows the rate of their spin. The most stable arrangement they can reach is to keep just one side always facing the body they are orbiting. Such "tidal locking" is why our moon always keeps the same face pointed toward Earth.

If the same were to happen with Earth and the sun, our planet would rotate once on its axis for every orbit it completed around the sun. In other words, an Earth day would

the moon with the Earth," study co-author Alexandre Correia said.

Computer models suggest that a giant impact from an asteroid then knocked it into its current strange configuration. The space rock would have been at least 43 miles (70 kilometres) wide and 550

be exactly as long as an Earth year, with one side receiving c o n s t a n t sunshine and the o t h e r e x p e r i e n c i n g perpetual night.

Now, researchers suggest that Mercury was once t ida l ly locked, initially spinning in the o p p o s i t e direction to its orbit.

"Mercury once had a spin rate s y n c h r o n o u s with the sun, like

A collision with an asteroid might have set the planet Mercury whirling oddly in its orbit, a new study suggests.

Asteroid crash may explain Mercury's strange spin

trillion metric tons in mass, or 1/600,000 the mass of Mercury, Correia said.

Evidence of this collision might include Caloris Basin, Mercury's largest impact crater, which matches the predicted size, age and location of the impact, the researchers said. "It is the perfect candidate," Correia said.

Such an impact might also explain certain hollows seen on Mercury's surface.

This photo of a Mercury crater seen by NASA's Messenger spacecraft shows what appears to be a large pit in the centre, possibly volcanic vent, from which the orange material erupted. Some odd hollows appear in cyan, a result of their high reflectance and bluish colour relative to other parts of the planet.


www.space.com

Above: This photo of a Mercury crater seen by NASA's Messenger spacecraft shows what appears to be a large pit in the centre, possibly volcanic vent, from which the orange material erupted. Some odd hollows appear in cyan, a result of their high reflectance and bluish colour relative to other parts of the planet.

Above: Hubble Space Telescope image showing Eta Carinae and the bipolar Homunculus Nebula which surrounds the star. The Homunculus was partly created in an eruption of Eta Carinae, the light from which reached Earth in 1843. Eta Carinae itself appears as the white patch near the centre of the image, where the 2 lobes of the Homunculus touch.

8. Avoid bright lights! When you are trying to observe faint objects in the night sky, any bright lights are your enemy. Leave a few minutes after leaving a brightly-lit room to allow your eyes time to adjust and become able to see dim light. Try to observe away from any lights which can create glare that interferes with your viewing. And if you need to consult a star chart or book, or swap eyepieces, be sure to use a red-light torch because that will not spoil your eyes’ dark-adaption like white light would.

9. Get to know the sky! Many modern telescopes are so clever that you can, in theory, stand them up in any position and they will happily find objects for themselves. In practice it is rarely quite so straightforward. In any case, it helps to learn about the sky at your own particular location. Get familiar with the directions of north, south, east and west. Try to recognise the main constellations and the brightest stars and note how they appear to move across the sky as the Earth rotates.

10. If all else fails, read the instructions or join a club! You may be tearing your hair out trying to set up your new telescope but do make sure you are doing everything by the book. Follow the manual, if you have one. Otherwise, for more advice on getting started with your new telescope you should always consider joining a local club which have experts available to give free advice.

www.skymania.com

instant gratif ication. But stargazing is a hobby where you may need to bide your time before getting any results. Apart from having to wait until it gets dark, you are at the mercy of the weather. Too often, a new telescope purchase seems to attract a run of cloudy nights! Even when it is clear, seeing conditions might not be ideal and if there is a lot of atmospheric turbulence, then your planet or star will dance around madly through a powerful eyepiece. Even when conditions are ideal, patience will help you see more. Instead of grabbing a ten-second look, let the eye linger. The longer you look, the more detail you will begin to see.

6. Don’t expect to see the same as Hubble! Magazines and books are filled with spectacular images of the Universe, many taken with powerful te l escopes a t profess iona l observatories or in space. But these only look bright and colourful because the telescopes are so big and are collecting the starlight over a period of many minutes. The human eye is a remarkable and sensitive thing but it will generally see night sky objects much more feebly, and you are unlikely to see any colour except in the brighter stars and planets.

7. Wrap up warm! It is hard to get enthusiastic about the Universe if you are shivering in the freezing cold. Even summer nights can seem pretty chilly unless you live somewhere tropical, so make sure you are dressed warmly. You could dig out your ski wear, otherwise wear a few layers to trap the body’s heat, topped with a fleece or woolly jumper and a wind-proof jacket. Thick-soled boots will stop your feet turning to ice and a hat, cap or balaclava will prevent too much body-heat escaping from your head!



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1. Get to know your scope. Whatever sort of controls your telescope has, it will be harder to master them in the dark, especially since astronomical telescopes usually show you objects upside down. So begin by making yourself familiar with the telescope during the day.

Aim at a distant object such as a pylon or a rooftop aerial. Use your controls, if you have them, to get it in the centre of your field of view and to sharpen the focus. This is a good way also to check that the telescope’s finderscope, if it has one, is properly in line with the main instrument and to adjust it if it isn’t. But DON’T EVER aim your telescope anywhere near the Sun which is so bright it could easily blind you.

2. Don’t magnify too much! Your telescope probably came with more than one eyepiece – that’s the little lens you look into – to give you different powers of magnification. When you have a new telescope, it is tempting to pump up the magnification as much as you can to see how big things can look. But a high-power eyepiece will make objects harder to find and will

magnify any little wobbles or vibrations in your mount as well as the view! It is best to start with a low-power eyepiece to help you find your target and to centre it in the field of view first. Then you can change the eyepiece to a higher-powered one if you must.

3. Start simply! When you use your telescope on the night sky, begin by observing bright objects such as the Moon or main planets like Jupiter and Saturn. They will be much easier to find, especially the Moon, and will be interesting too. The Moon is a great target for a small telescope because it is relatively close to us as our nearest neighbour in space and has a surface covered with eye-popping features.

4. Don’t get the shakes! Place your telescope on a stable surface. Some small telescopes come with a correspondingly tiny mounting and are designed to be used on a table top. Bigger telescopes may come with a tripod so that they stand on the ground. In either case, make sure they stand as solidly as they can to avoid too much vibration (see rule 2!). Make sure that the table is not

too rickety or that the ground is nice and flat. A g r a s s y lawn is a b e t t e r place to stand a tripod than a concrete

patio because it will be better at dampening those pesky vibrations.

5. Be patient! We live in an age when many people expect

To help find your way around the night sky, Skymaps.com makes available for free each month a map of the night sky.

The Evening Sky Map is suitable for all stargazers including newcomers to astronomy and will help you to:

• identify planets, stars and major

constellations.

• find sparkling star clusters, wispy

nebulae & distant galaxies.

• locate and follow bright comets

across the sky.

• learn about the night sky and

astronomy.

If you have just bought or been given a new telescope, you are sure to be keen to use it straight away to see what spectacles the night sky can offer, whether it be the Moon, planets, stars, gas clouds or galaxies. Here are ten useful tips to help ensure that you are not disappointed.

Ten tips for using a new telescope

Top Astronomy events coming up in 2012

Conjunction of Venus and Jupiter On March 14th the Planets Venus and Jupiter will be within 3 degrees and very close to each other in the early evening sky. This will be quite a spectacle as both planets are very bright (Venus being the brightest) and the pair will burn brightly together like a pair of alien eyes watching us after the Sun sets.

This conjunction (where planets group close together as seen from Earth) will be a fantastic visual and photographic opportunity, as it’s not often you get the brightest Planets in our Solar System so close together.

Transit of Venus For many, the transit of Venus is the year’s most anticipated astronomical event and it takes place on June 5th – 6th. The Planet Venus will pass between the Earth and the Sun and you will see Venus (a small black circle) slowly move across, or “transit” the disc of the Sun. Transits of Venus are very rare and only a few have been witnessed since the dawn of the telescope. Be sure not to miss this very rare event as the next one isn’t visible for over another 100 years from now in 2117 and the

This has been the subject of much discussion, comedy and media coverage, and it has even been made into films.

All I know is 2012 is going to be a great year for astronomy with some very interesting, rare events taking place, with many more regular events to see into 2013 and beyond.


Jupiter and the Moon European observers are in for a very rare treat as the Moon briefly hides the planet Jupiter on the morning of July 15th. This “lunar occultation” can be seen from southern England and parts of Europe at approximately 1:50am (dependant on location) and the planet re-emerges from the dark lunar limb at approximately 3:10am . This is a great chance to watch this rare and bright event, and it will also be a fantastic imaging opportunity.

Annular Eclipse American observers will have treat on May 20th with an annular eclipse of the Sun. The eclipse will be visible from many western US states and a partial eclipse visible from most of North America.

Because the Moon’s orbit is not a perfect circle and is slightly elliptical, it moves closer and further away from us slightly in its orbit and on July 15th it is at its furthest point away from the Earth as it passes in front of the Sun. Normally the Moon covers the entire disc of the Sun and creates a total solar eclipse, but because the Moon is at its furthest point in its orbit on the 15th, we get an annular eclipse, where we can still see a ring of bright light around the Sun, but we don’t get totality.

The World Not Ending Finally we get to December 21st, in which astronomy-minded folks will celebrate the solstice. But in case you haven’t heard, some have prophesied the end of the world, saying the Mayan calendar ends.

next after that is in 2125. For us in Ireland we will only be able to see the last part of the transit as the Sun rises.

Never ever look directly at the Sun and never look at it through a normal telescope or binoculars – You will be permanently blinded!

Meteor Showers 2011 was a poor year for meteor showers due to the presence of a largely illuminated Moon on most showers; this prevented all but the brightest meteors being seen.

In contrast 2012 brings a welcome respite from the glare of the Moon as it gives little or no interference with this year’s major showers. The only other issue left to contend with is the weather, but if you have clear skies on the evenings of these celestial fireworks, you are in for a treat.

The Perseid Meteor Shower peaks on the morning of the 12th August. Perseids are the most popular meteor shower of the year as it tends to be warm and the shower has very bright meteors and fireballs, with rates of 100+ an hour at its peak.

The Geminid Meteor Shower is probably the best meteor shower of the year with high rates of s l o w b r i g h t meteors. The peak is very broad and rates of 100+ meteors per hour can be seen. The best time to look out for Geminids is on the evenings of the 12th to 14th December, but they can be seen much ear.

2012 is going to be a great year for astronomy observing, with some rare and exciting things taking place and a good outlook with some of the regular annual events. So what top wonders should we expect to see and what will 2012 bring?

Above: The transit of Venus will look similar to this image.


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The reflected light has its properties changed by the motion of the material off which it reflects. In particular, the light shows a no t ab le b l uesh i f t , t e l l i n g astronomers that the material itself is traveling 210 km/sec.

This observation fits with theoretical predictions of eruptions similar to the type η Carinae is thought to have undergone. However, the light echo has also highlighted some discrepancies be tween expec ta t i on and observation.

Light echoes have been made famous in recent years by the dramatic example of V838 Monocerotis. While V838 Mon looks like an expanding shell of gas, what is actually depicted is light reflecting off shells of gas and dust that was thrown off earlier in the star’s life.

The extra distance the light had to travel to strike the shell, before being reflected towards observers on Earth, means that the light arrives later. In the case of η Carinae, nearly 170 years later!

Typically, η Carinae’s eruption is classif ied as a “supernova impostor”. This title is fitting since the eruptions create a large change in the overall brightness. However, although these events may release 10% of the total energy of a typical supernova or more, the star remains intact.

The main model to explain such eruptions is that a sudden increase in the star’s energy output causes some of the outer layers to be blown off in an opaque wind. This shell of material is so thick, that it gives a large increase in the effective surface area from which light is emitted, thereby increasing the overall brightness.

However, for this to happen, mode l s p r ed i c t t h a t t h e temperature of the star prior to the eruption needs to be at least 7,000 K. Analysing the reflected light from the eruption places the temperature of η Carinae at the time of the eruption at a much lower 5,000 K. This would suggest that the favoured model for such events is incorrect and that another model, involving an energetic blast was (a mini-supernova), may be the true culprit, at least in η Carinae’s case.

Echoes from η Carinae’s great eruption During the mid 1800′s, the well known star η Carinae underwent an enormous eruption becoming for a time, the second brightest star in the sky. Although astronomers at the time did not yet have the technology to study one of the largest eruptions in recent history in depth, astronomers from the Space Telescope Science Institute recently discovered that light echoes are just now reaching us. This discovery allows astronomers to use modern instruments to study η Carinae as it was between 1838 and 1858 when it underwent its Great Eruption.

The core is composed of iron, rock and ice and weighs about ten times as much as Earth. That’s still small though, compared to the overall mass of Jupiter itself, which weighs as much as 318 Earths! The core is buried deep within the thick atmosphere of hydrogen and helium. Conditions there are brutal, with a temperature of about 16,000 kelvin – hotter than the surface of the Sun – and a pressure about 40 million times greater than the atmospheric pressure on Earth. The core is surrounded by a fluid of metallic hydrogen which results from the intense pressure deep down in the atmosphere. The bulk of Jupiter though is the atmosphere itself, hence why Jupiter (and

like at genesis. Did it have a substantial core at that time? If so, was it 10 Earth masses, 15, 5?”

The findings also mean that some exoplanets which are even larger and more massive than Jupiter, and thus likely even hotter at their cores, may no longer have any cores left at all. They would be indeed be gas giants in the most literal sense.

Saturn, Uranus and Neptune) are called gas giants.

One of the primary ingredients in the rock of the core is magnesium oxide (MgO). Planetary scientists wanted to see what would happen when it is subjected to the conditions found at the core; they found that it had a high solubility and started to dissolve. So if it is in a state of dissolution, then it was probably larger in the past than it is now and scientists would like to understand the process. According to David Stevenson of the C a l i f o r n i a I n s t i t u t e o f Technology, ”If we can do that, then we can make a very useful statement about what Jupiter was

Jupiter, the largest and most massive planet in our solar system, may be its own worst enemy. It turns out that its central core may in fact be self-destructing, gradually liquefying and dissolving over time. This implies it was previously larger than it is now, and may dissolve altogether at some point in the future. Will Jupiter eventually destroy itself completely? No, probably not, but it may lose its heart…

Is Jupiter’s core liquefying?




Yet this observation is somewhat at odds with observations made in the years following the eruption. As spectrography came into use, astronomers in 1870 visually noticed emission lines in the star’s spectrum which is more typical in hotter stars.

In 1890, η Carinae had a smaller eruption and a photographic spectrum put the temperature around 6,000 K. While this may not accurately reflect the case of the Great Eruption, it is still puzzling how the star’s temperature could change so quickly and may also indicate that the favoured model of the opaque-wind model is a better fit for later times or the smaller eruption, which would suggest two different mechanisms causing similar results in the same object on short timescales.

Either way, η Carinae is a marvellous object. The team has also identified several other areas in the shell surrounding the star which appear to be brightening and undergoing their own echoes which the team promises to continue to observe which would allow them to verify their findings.


Above: Eta Carinae (η Carinae or η Car) is a stellar system in the constellation Carina, about 7,500 to 8,000 light-years from the Sun.

When one body orbits another — say, a moon around a planet or a planet around a star — the orbiting body often spins. Our planet experiences day and night because it spins on its axis, regularly changing which side it exposes to the sun.

However, the gravitational pull that orbiting moons and planets experience slows the rate of their spin. The most stable arrangement they can reach is to keep just one side always facing the body they are orbiting. Such "tidal locking" is why our moon always keeps the same face pointed toward Earth.

If the same were to happen with Earth and the sun, our planet would rotate once on its axis for every orbit it completed around the sun. In other words, an Earth day would

the moon with the Earth," study co-author Alexandre Correia said.

Computer models suggest that a giant impact from an asteroid then knocked it into its current strange configuration. The space rock would have been at least 43 miles (70 kilometres) wide and 550

be exactly as long as an Earth year, with one side receiving c o n s t a n t sunshine and the o t h e r e x p e r i e n c i n g perpetual night.

Now, researchers suggest that Mercury was once t ida l ly locked, initially spinning in the o p p o s i t e direction to its orbit.

"Mercury once had a spin rate s y n c h r o n o u s with the sun, like

A collision with an asteroid might have set the planet Mercury whirling oddly in its orbit, a new study suggests.

Asteroid crash may explain Mercury's strange spin

trillion metric tons in mass, or 1/600,000 the mass of Mercury, Correia said.

Evidence of this collision might include Caloris Basin, Mercury's largest impact crater, which matches the predicted size, age and location of the impact, the researchers said. "It is the perfect candidate," Correia said.

Such an impact might also explain certain hollows seen on Mercury's surface.

This photo of a Mercury crater seen by NASA's Messenger spacecraft shows what appears to be a large pit in the centre, possibly volcanic vent, from which the orange material erupted. Some odd hollows appear in cyan, a result of their high reflectance and bluish colour relative to other parts of the planet.


www.space.com

Above: This photo of a Mercury crater seen by NASA's Messenger spacecraft shows what appears to be a large pit in the centre, possibly volcanic vent, from which the orange material erupted. Some odd hollows appear in cyan, a result of their high reflectance and bluish colour relative to other parts of the planet.

Above: Hubble Space Telescope image showing Eta Carinae and the bipolar Homunculus Nebula which surrounds the star. The Homunculus was partly created in an eruption of Eta Carinae, the light from which reached Earth in 1843. Eta Carinae itself appears as the white patch near the centre of the image, where the 2 lobes of the Homunculus touch.



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In late 2006, observers at the Catalina Sky Survey in Arizona found an object orbiting the Earth. At first, it looked like a spent rocket stage — it had a spectrum similar to the titanium white paint NASA uses on rocket stages that end up in heliocentric orbits. But closer inspection revealed that the object was a natural body. Called 2006 RH120, it was a tiny asteroid measuring just a few metres across but it still qualified as a natural satellite just like the Moon. By June 2007, it was gone. Less than a year after it arrived, it left Earth’s orbit in search of a new cosmic companion.

They found that the Earth-Moon system captures NEOs quite frequently. “At any given time, there should be at least one natural Earth satellite of 1-meter diameter orbiting the Earth,” the team said. These NEOs orbit the Earth for about ten months, enough time to make about three orbits, before leaving.

L u c k i l y , a n d v e r y interestingly, this discovery has implication well beyond academic applications.

Knowing that these small satellites come and go but that one is always present a r o u n d t h e E a r t h , astronomers can work on detecting them. With more complete information on these bodies, specifically their position around the Earth at a given time, NASA could send a crew out to investigate. A crew wouldn’t be able to land on something a few metres across, but they could certainly study it up close and gather samples.

Proposals for a manned mission to an asteroid have been floating around NASA for years. Now, astronauts won’t have to go all the

Now, astrophysicists at Cornell are suggesting that 2006 RH120 wasn’t an anomaly; a second temporary moon is actually the norm for our planet.

These temporary satellites are a result of the gravitational pull of Earth and the Moon. Both bodies pull on one another and also pull on anything else in nearby space. The most common objects that get pulled in by the Earth-Moon system’s gravity are near Earth objects (NEOs) — comets and asteroids are nudged by the outer planets and end up in orbits that

bring them into Earth’s neighbourhood.

The team from Cornell, astrophysicists Mikael G r a n v i k , J e r e m i e Vauba i l l on , R obe r t Jedicke, has modeled the way our Earth-Moon system captures these NEOs to understand how often we have additional moons and how long they stick around.

way out to an asteroid to learn about the Solar System’s early history. NASA can wait for an asteroid to come to us.

If the Cornell team is right and there is no shortage of second satellites around the Earth, the gains from such missions increases. The possible information about the solar system’s formation that we could obtain would be amazing, and amazingly cost-efficient.


dimmest performance in recorded history, though it's been reliably bright over the past millennia. This most famous of comets has a rich historical background that makes it rewarding to observe. Known since antiquity, the comet served as an omen over the centuries, and marked many historical events, including the Battle of Hastings in 1066, and the invasion of Europe by Genghis Khan in 1222.

The comet also gave Edmund Halley a chance to test Newton's newly discovered laws of gravitation, and determine that several historical comets were actually the same comet that returned every 76 years.

Halley predicted this comet's return in 1758, and he was correct. While he didn't live long enough to see it himself, his name remains associated with this

While a half-dozen comets come and go each year, most are too faint to see without optical aid. But a bright comet, with a swollen head brighter than Venus and a tail streaking a third of the way across the sky is a stunning and unnerving sight, one that should be seen by even the most casual stargazer. It's a sight you'll never forget, and it comes in at #3 on our Bucket List.

By cosmic standards, a comet doesn't amount to much. It's a tiny remnant of the formation of the solar system, a dusty ice ball a few kilometres across that floats unseen in the outer reaches of the solar system.

But from time to time, a passing star or giant molecular cloud gives an anonymous comet a little nudge, and it starts a long journey towards the inner solar system. If the timing and mechanics are right, such a comet may put on a spectacular show in the night sky.

On average, a bright and truly spectacular comet comes about once a decade. The last was Comet McNaught in 2007, a dazzling sight for southernhemisphere observers that (so far) is considered the “comet of the century”. Before that, there were the back-to-back appearances of Comet Hale-Bopp and Comet Hyukutake in 1997 and 1996. And before that, Comet West put on a lovely show in the pre-dawn skies in 1976. There have been other dazzlers, too, including three comets in the 19th century bright enough to see in the daytime sky, and a fourth that appeared early in 1910.

The return of Comet Halley was a dud in 1986. The comet gave its

periodic visitor. Halley's Comet is the brightest of the short-period comets that return to the inner solar system every few years or decades. But most bright comets have orbital periods measured in thousands of years. And some

bright comets visit just once, never to return.

Mos t b r igh t come ts a r r i ve unpredictably from the distant Oort Cloud. They're often discovered accidentally by amateur and professional astronomers with large telescopes and complex imaging equipment.

No photograph or experience can prepare you for the magnificent and ghastly sight of a bright comet in the night sky. When you see one, you understand why they caused such fear in more superstitious times. The apparent size of the coma, or head, of the comet can be larger than any other sight save the Moon or Sun. And the tail can display lovely fine structure and filaments that can change over the course of minutes and hours. No other celestial object matches its appearance.

The great Mark Twain was born during the return of Halley's Comet in 1835. In 1909, he predicted his life would end with the comet's return. “The Almighty has said, no doubt”, wrote Twain, “Now here are these two unaccountable freaks; they came in together, they must go out together”. Twain died in April, 1910, a day after Comet Halley made its closet approach to the Sun.

It's hard to arrange your life around a comet (as did Mark Twain), but a careful and leisurely examination of a bright comet is a delightful event in the life of any stargazer. When one comes along, make sure you see it, savour it, and cross it off your celestial bucket list.

www.oneminuteastronomer.com

New research suggests that a second temporary moon orbiting the Earth is actually the norm for our planet.

Earth’s other Moons Bucket List Object #3: A Bright Comet

Over the next several months, we present our totally subjective list of ten celestial sights to see before you die, or “kick the bucket”, as they say. We call it the “Bucket List for Backyard Stargazers”. Our list is targeted at the casual stargazer, with no special expertise or training or ambition other than to see some of the most beautiful, and in some cases, transient sights in nature. For some of these objects, you’ll need access to a pair of binoculars or a small telescope. Others require travel and good timing and luck. And for others, you need to simply look up. But all these sights are not that hard to see, once you know how and when and where to look for them. We’ll help you with that.

Left: Comet P1

McNaught, taken from

Victoria, Australia in 2007.

The findings come from the Hubble Space Telescope, using the new and highly sensitive Cosmic Origins Spectrograph which indicate that there is a strong ultraviolet-wavelength absorber on the surface. This absorbing material is thought to likely be complex hydrocarbons and/or nitriles.

Pluto’s surface is known to be coated with ices composed of methane, carbon monoxide and nitrogen. The putative molecules can be produced by sunlight or cosmic rays interacting with them.

Have complex molecules been found on Pluto’s surface?

“This is an exciting finding because complex Plutonian hydrocarbons and other molecules that could be responsible for the ultraviolet spectral features we found with Hubble may, among other things, be responsible for giving Pluto its ruddy colour,” said project leader Dr. Alan Stern.

The team also found evidence for surface changes in the ultraviolet spectrum, comparing current observations to those from the 1990s. The cause may be an increase in the pressure of Pluto’s

First there was the recent story about evidence for a possible subsurface ocean on Pluto, of all places. Now there is a new report regarding evidence for complex molecules on its surface, from scientists at Southwest Research Institute and Nebraska Wesleyan University. Little enigmatic Pluto is starting to get even more interesting…

t e n u o u s atmosphere or different terrain which i s be ing viewed at d i f f e r e n t times.

With all of the new d i s cover i es already being made about P luto, i t should be v e r y i n t e r e s t i ng when New Horizons gets there in 2 0 1 5 , providing us with the first close-up look of this fascinating little world.


Left: Artist's conception of New Horizons during its flyby of Pluto in 2015.

Above: Saturn's moons Rhea and Dione as seen by the Cassini spacecraft. Could this be a future view from Earth?

Above: Near Earth object Eros, the

type of object that could be a second


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smaller, rocky planets. This is a different structure from our solar system, where the rocky worlds are closer to the sun while the gas giants have more outlying orbits.

To find planets around sunlike stars, the Kepler spacecraft continually observes one section of sky within the constellations Cygnus and Lyra. In this field of view, Kepler detects changes in the brightnesses of individual stars, which may indicate the presence of planets transiting—or passing in front of—a star, as seen from Earth.

To date, the Kepler mission has identif ied more than 2,300 exoplanet candidates—worlds that are suspected of orbiting other stars but that need more observations to be confirmed.

Further observations will be needed

contrast, Earth's average surface temperature is 57.2ºF (14°C).

Still, this is the first confirmation of truly Earth-size planets by the Kepler team—a key goal of the overall mission. "December 2011 may be remembered as the first time humanity was able to discover an Earth-size planet in orbit around another star," lead author Francois Fressin said today during a NASA teleconference. The discovery "demonstrates for the first time that Earth-size planets exist around other stars, and that we are able to detect them."

Previously discovered exoplanets have all been considerably larger than Earth. Even the just announced Goldilocks world, Kepler-22b, was estimated to be 2.4 times Earth's radius and is thought to have a fairly low density, meaning it could have a thick atmosphere and a surface quite unlike Earth's.

A curious feature of the Kepler-20 system is that the other three known planets, which are Neptune-size worlds, orbit among the

The find comes on the heels of Kepler's first potentially Earthlike planet orbiting squarely within its star's water-friendly "Goldilocks zone"—the region that's not too hot and not too cold for liquid water to exist on a planet's surface.

Designated Kepler-20e and Kepler-20f, the two new planets are comparable in size to Earth and Venus: At 0.87 times the size of Earth, Kepler-20e is slightly smaller than Venus, while Kepler-20f is 1.03 times Earth's radius. But both new extraso lar p lanets—or exoplanets—orbit their star much too closely to be within the habitable zone.

In fact, the entire Kepler-20 system is believed to contain at least five planets all orbiting their star within a distance smaller than that between Mercury and the sun.

This orbital distance makes the planets very hot. For instance, Kepler-20e is estimated to have an average surface temperature of 1,400ºF (760ºC), while Kepler-20f is a "cooler" 800ºF (427ºC). By

Two new planets found orbiting a sunlike star are the first truly Earth-size worlds discovered by NASA's Kepler mission, scientists recently announced.


NASA's Kepler finds two Earth-size Planets around

sunlike Star

Kid’s�Korner�

Above: A size comparison of two new planets with Earth and Venus.

to find that "holy grail" of exoplanet discovery: an Earth-size world located within a sunlike star's habitable zone—and possibly even containing liquid water on its surface.

"What drives the Kepler team is cont inuing to f ind smaller exoplanets farther from their stars we need more data." But for that to happen, the Kepler mission will need more time—and that could require a mission extension. For now, the project is slated to end in November 2012.

Still, even with the current mission time line, "we are hoping to announce in the next two years the discovery of an Earth-size, habitable exoplanet."


perspect ive, s ince i t was presumably formed in the same explosion that produced the supernova remnant. Assuming that it was born with rapid spin, it is a mystery why SXP 1062 has been able to slow down by so much, so

First ever Pulsar found in a Supernova Remnant

quickly. Work has already begun on theoretical models to understand the evolution of this unusual object.

The diffuse X-rays and optical shell are both evidence for the supernova remnant surrounding the pulsar. The optical data also displays spectacular formations of gas and dust in a star-forming region on the left side of the image. A comparison of the Chandra image with optical images shows that the pulsar has a hot, massive companion.

Astronomers are interested in SXP 1062 because the Chandra and XMM-Newton data show that it is rotating unusually slowly -- about once every 18 minutes. In contrast,

some pulsars are found to revolve multiple times per second, including most newly born pulsars. This relatively leisurely pace of SXP 1062 makes it one of the slowest rotating X-ray pulsars in the SMC.

In the image top of page X-rays from Chandra and XMM-Newton have been colored blue and optical data from the Cerro Tololo Inter-American Observatory in Chile are colored red and green. The pulsar, known as SXP 1062, is the bright white source located on the right-hand side of the image in the middle of the diffuse blue emission inside a red shell.

www.dailygalaxy.com

Two different teams of scientists have estimated that the supernova remnant around SXP 1062 is between 10,000 and 40,000 years old, as it appears in the image. This means that the pulsar is very young, from an astronomical

Data from NASA's Chandra X-ray Observatory and ESA's XMM-Newton have been combined to discover a young pulsar in the remains of a supernova located in the Small Magellanic Cloud, or SMC. This would be the first definite time a pulsar, a spinning, ultra-dense star, has been found in a supernova remnant in the SMC, a small satellite galaxy to the Milky Way.

Build your own rocket using paper and fizzing tablets! Watch it lift off. How high does your rocket go? Print this page for the instructions.

Suggestion: Find a grown-up to do this activity with you.

Materials:

• Paper, regular 8-1/2-

by 11-inch paper, such as computer printer paper or even notebook paper.

• Plastic 35-mm film canister (see

hints below)

• Cellophane tape

• Scissors

• Effervescing (fizzing) antacid

tablet (the kind used to settle an upset stomach)

• Paper towels

• Water

• Eye protection (like eye glass-

es, sun glasses, or safety glass-es)

Hints: Right kind of film canister - The film canister MUST be one with a cap that fits INSIDE the rim instead of over the outside of the rim. Sometimes photography shops have extras of these and will be happy to donate some for such a worthy cause.

Keep in mind: Just like with real rockets, the less your rocket weighs and the less air resistance (drag) it has, the higher it will go.

Making the Rocket: You must first decide how to cut your paper. You may cut it the short way or the long way to make the body of the rocket. There is no

one right way to make a paper rocket. Try a long, skinny rocket or a short, fat rocket. Try a sharp nosecone or a blunt nosecone. Try it with fins or without fins. Experiment!

Here's just one idea for how you might cut your whole rocket from one piece of paper:

Here are the basic steps: Young rocket engineer

1. Cut out all the pieces for your rocket.

2. Wrap and tape a tube of paper around the film canister. Hint: Tape the canister to the end of the paper before you start wrapping. Important! Place the lid end of the canister down.

3. Tape fins to your rocket body, if you want.

4. Roll the circle (with a wedge cut out) into a cone and tape it to the rocket's top.

Blasting Off 1. Put on your eye protection. 2. Turn the rocket upside down

and remove the canister's lid. 3. Fill the canister one-third full of

water. Now work quickly on the next steps!

4. D r o p o n e - h a l f o f a n effervescing antacid tablet into the canister.

5. Snap the lid on tight. 6. Stand your rocket on a launch

platform, such as your sidewalk or driveway.

7. Stand back and wait. Your rock-et will blast off!

Roll this long piece around the film canister for the rocket body

Tape canister to the edge of paper before you start rolling paper around canister.

For a nosecone, use a jar lid or something like that to trace the circle required.

Above: A finished rocket ready for lift-off.

Build a Bubble Powered Rocket!

http://www.marcsobservatory.com/default.html


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c o n t e n t sc o n t e n t sc o n t e n t sc o n t e n t s Latest Astronomy and Space News NASA's Kepler finds two Earth-size Planets around sunlike Star ......................................................................... 3

First ever Pulsar found in a Supernova Remnant ................... 3

Earth’s other Moons ............................................................ 4

Have complex molecules been found on Pluto’s surface? ....... 4

Echoes from η Carinae’s great eruption ................................ 5

Ten tips for using a new telescope ....................................... 6

Top Astronomy events coming up in 2012 ............................ 7

Is Jupiter’s core liquefying? .................................................. 8

Asteroid crash may explain Mercury's strange spin ................ 8

Bucket List Object #3: A Bright Comet ................................. 9

Kids Section Kids Korner ....................................................................... 10

Quizzes and Games Exercise your brain ............................................................ 11

Monthly Sky Guide Beginners sky guide for this month .................................... 12

Internet Highlights Special content only available with the online version of the magazine ................................................................ 13

Front cover image: Two galaxies colliding galaxies in Corvus but the stars that compose them usually do not

crash into each other. That's because galaxies are mostly empty space and,

however bright, stars only take up only a small amount of that space.

During the slow, hundred million year

collision, one galaxy can still rip the other apart gravitationally, and dust and gas

common to both galaxies does collide. In this clash of the titans, dark dust pillars mark

massive molecular clouds are being compressed during the galactic encounter, causing the rapid birth of millions of stars, some of which are gravitationally bound

together in massive star clusters.

Credit & Copyright: INASA, ESA & B. Whitmore (STScI) et al.

MAC meets on the first Tuesday of

the month in the Presbyterian Hall, High Street, Tullamore from 8pm.

All are welcome to attend. It also holds infrequent Observing

Nights at its Observing Site in

Clonminch, or at a member’s house (weather permitting) on the first

Friday of every month..

You can see more about the club and its events on


or contact the club via e-mail at [email protected]

Meetings are informal and are aimed at a level to suit all ages.

Exercise your brainExercise your brainExercise your brainExercise your brain 1. What is a bright streak

of light seen in the sky?

� Meteorite

� Asteroid

� Meteroid

� Meteor

2. Light travels at 186,282 miles per ___________

� hour

� minute

� second

� year

3. What is a depression on

a terrestrial planet or

satellite called?

� Hill

� Crater

� Mountain

� Ridge

4. The uppermost region

of the Sun is called the?

� Photosphere

� Ionosphere

� Chromosphere

� Corona

5. A medium sized icy solar system object is called

a?

� Asteroid

� Planet

� Comet

� Star

1

9 3 4 8

6 7 5 2 1

1 3 7 8

1 5 2 4

4 7 6 5

7 5 6 1 4

1 2 4 9

9

SUDOKU

Check your answers

Answer 1: The correct answer was Mete-or. A meteroid is the object before it

encounters the Earth's atmosphere. A meteorite is the object that survives the

journey through the atmosphere to im-pact on the Earth. Asteroids are objects made of rock and iron and most are in the

main asteroid belt between Jupiter and Mars.

Answer 2: The correct answer was second or about 300,000 kilometers a second.

The nearest star system to our Sun is some 4.3 light years away. This is easier to say than 25 trillion miles away.

Answer 3: The correct answer was Crater. Craters are mostly oval or round in shape.

They result when an asteroid or comet impacts a world.

Answer 4: The correct answer was Coro-na. The corona is what we see during a

total solar eclipse. The chromosphere is between the photosphere and the corona of the Sun. The ionosphere is the upper

part of a planet's atmosphere.

Answer 5: The correct answer was Comet.

Comets are mostly ice and rock with some dust and asteroids are mostly rock and

metal.

Answer 6: The correct answer was Bolide.

A fireball is a meteor that is brighter than -3 magnitude, almost as bright as the

planet Venus gets.

Answer 7: The correct answer was Magni-

tude. The magnitude system was actually invented by Hipparchus, an astronomer

that lived from 190 B.C. to 120 B.C.

Answer 8: The correct answer was a

parsec. A parsec is the distance from the Sun which results in a parallax of 1 se-cond of arc. One astronomical unit is the

mean distance between the Sun and the Earth. The nearest star is 1.3 parsecs

away (Proxima Centauri).

Answer 9: The correct answer was Plage.

These are bright regions seen in the Sun's chromosphere. Sunspots are "cooler" regions on the Sun. Prominences follow

the Sun's electromagnetic lines and flow back into the Sun. Flares are matter that

has been ejected from the Sun in a violent explosion, this matter does not return to the Sun but continues out into the solar

system.

Answer 10: The correct answer was

Retrograde. Triton (Neptune's satellite) is the largest satellite that is retrograde

around its planet. There are smaller satellites in the solar system that are also retrograde around their planet.

Confused???

Check your answers on this page.

6. What is a fireball that

produces a sonic boom called?

� meteorite

� No such object

� Bolide

� Comet

7. What is the brightness

scale of stars called?

� Magnitude

� Temperature

� Albedo

� Density

8. 3.26 light years is called?

� an astronomical Unit

� the distance to the

nearest star

� nothing

� a parsec

9. What is a bright region in the Sun called?

� Prominence

� Sunspot

� Plage

� Flare

10.What is the name for

an object that goes around another object

backwards called?

� Retrograde

� Upside down

� Prograde

� Normal

Above: Orion includes the prominent asterism known as the 'belt' of Orion: three bright stars in a row. Surrounding the belt at roughly similar distances are four bright stars, which are considered to represent the outline of the hunter's body. Descending from the 'belt' is a smaller line of three stars (one of which is in fact not a star but the Orion Nebula), known as the hunter's 'sword'. Right: The Crab Nebula (M1) in the constellation Taurus.

satellites and details on the planet’s surface with the rings out of the picture. Venus is visible in the early morn ing hours b laz ing at magnitude -4.1. Venus shows phases through the telescope similar to the moons phases. Watch Venus weekly as it grows in apparent size and the phases shift.

Wel l , that 's about i t for January's picks although with a good star map there are tons of wonderful sights to be had on cold winter nights. Clear skies and good hunting!

out to where the V seems to end at another fairly bright star (Zeta Tauri). Go up toward the other side of the V about a fifth of the distance toward the other star (El Nath) and you should see a dim "fuzz." Dark skies are needed for this one though.

Planets J u p i t e r c o n t i n u e s t o b e available in the early evening with Saturn following Jupiter across the sky. Saturn can be located in Leo this month. With the planet’s ring plane almost edge on, this is not a good time to try and observe the rings. It is however a good time to try and observe the smaller

Alnitak

Crab Nebula

them easily with my 4.5" reflector. In the same telescopic view, more or less attached to M42 is M43, a small patch of nebulosity separate from M42.

We also have a nice multiple star system in Orion, Sigma Orionis. To find this system, use the eastern most star of Orion's belt (Alnitak). Just below Alnitak is a dimmer star, this is Sigma Orionis. Focus in on this star at high power, and it should split into what looks like 3 separate stars. In most small telescopes, Sigma Orionis will look like a triple star. Also in the same field of view is another triple star system known as Struve 761.

Also in Orion are many double stars. Alnitak is a tough double to split with a separation of only 2.4 arc-seconds. Mintaka (the star on the right side of the belt). The companion is somewhat dim glowing at only 7th magnitude.

Also up for January is a super-nova remnant (SNR), the Crab Nebula. This is the remains of a star that exploded in 1054AD which makes this a youngster in astronomical terms. Up and to the right of Orion there is a "V" shaped grouping of stars (the head of Taurus the Bull). The Hyades are part of this V as well. A very bright orange-red star (Aldeberan) sits as the third star in the line of the V. follow this line

For the naked eye in January, we have another meteor shower to look forward to. The Quadrantids generally begin on January 1st and end on January 7th, with the maximum occurring this year on the evening of the 4th. The shower coincides with the moon so moonlight will not interfere with observing at any hour of the night. Observers in the Northern Hemisphere can see around 60 meteors per hour or more at m a x i m u m . L o o k f o r meteors radiating from the constellation Bootes near the plough/big dipper.

Telescope Targets Many of Autumn's targets are still available early in the evening. See November's and December's picks for these.

For January, Or ion reigns supreme in the sky. One of the brightest and best nebula is the Great Orion Nebula (M42). This is also one of the easiest (if not the easiest) deep sky targets to locate. Hanging from the belt of Orion (3 stars in a row of equal magnitude) are 3 more stars (his sword). The second "star" of these is the nebula. Folks with good eyes can make out colour (typically green) at higher powers. Push the power up and look for the 4 stars in the centre that provide the luminosity for this nebula. These are known as the trapezium and I have seen


Page - 12

Midlands Astronomy Club Magazine

Issue 30- January, 2012

Latest Astronomy and Space News

Kids Astronomy

Quizzes and Games

Monthly Sky Guide

Internet Highlights

Sky Guide - Beginner’s targets for January

Club Notes

Club Observing:

Remember the next club meets every first Friday of the month for our observing sessions held in the MAC grounds. If you wish

to be informed of these sessions please email your name and mobile number to [email protected] who will con-

firm if the session is going ahead (depending on weather).

MAC is a proud member of


Page - 14 Page - 13

Each month we will try and bring you the best of the web for astronomy online resources such as movies, podcasts and free software. If you have any suggestions for content in these pages please contact us at [email protected]

Please click on the links provided to view the material and not the images.

Explore the biggest question of all... How far do the stars stretch out into space? And what's beyond them? In modern times, we built giant telescopes that have allowed us to cast our gaze deep into the universe. Astronomers have been able to look back to near the time of its birth. They've reconstructed the course of cosmic history in astonishing detail.



Cosmic Journeys: Is the Universe infinite?

Internet Highlights

Useful free astronomy resources

IFAS Website h p://www.irishastronomy.org

Stellarium h p://www.stellarium.org

Virtual Moon Atlas h p://www.astrosurf.com/avl/UK_index.html

Celes'a h p://www.sha ers.net/celes'a/index.html

Sky Maps h p://skymaps.com/index.html

Heavens-Above h p://www.heavens-above.com/

This Year @ NASA, 2011

http://youtu.be/SB_Qfngi0mo

Greatest Astronomy Discoveries

First Earth sized exoplanets found by Kepler

http://www.nasa.gov/multimedia/videogallery/index.html?media_id=125475311

Podcast: Io

http://www.astronomycast.com/

Destination Innovation Episode 1 - Kepler

Episode 1 of this new series focuses on the Kepler Mission, a space telescope that is revolutionizing our knowledge of planets outside our Solar System.

http://youtu.be/ArLEfh8GbEY

Midlands Astronomy Club have created a Facebook page so that our members and non-members alike can:

• Keep up-to-date on future out-

reach events.

• Be informed of upcoming

lectures.

• Have online access to the

latest astronomy news as it happens.

• See photos of all club events

and activities.

Find us on www.facebook.com

If you want to see one of the strangest places in the Solar System, look no further than Io, Jupiter’s inner Galilean moon. The immense tidal forces from Jupiter keep the moon hotter than hot, with huge volcanoes blasting lava hundreds of kilometres into space.

Podcast: The Jodcast

http://www.jodcast.net/archive/

A podcast about astronomy including the latest news, what you can see in the night sky, interviews with astronomers and more. It is created by astronomers from The University of Manchester's Jodrell Bank for anyone interested in things out of this world.

http://youtu.be/dG1JpC5jels

The violent end stage of Star formation

http://www.nasa.gov/multimedia/videogallery/index.html?media_id=125903691

EsoCast showcases a new Hubble image of a giant cloud of hydrogen gas illuminated by a bright young star. The image shows how violent the end stages of the star

formation process can be, with the young object shaking up its stellar nursery.

http://youtu.be/S_nCIJnZDW8

mac january 2012 magazine

Documents

dimmer star

triple star system

good star map

star of orions belt

belt of orion

orion nebula

bright star zeta tauri

bright stars