meteor showers
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Meteor Showers
What's the Source of Meteor Showers?
Comets ...
... and Asteroids!
Nucleus of Comet Halley from the Giotto Probe
How It Works ...
Comet
Movie
Meteor Shower Movie
Meteors and Meteorites: When bits of dust from asteroids and comets (meteoroids) hit
Earth's atmosphere, they burn up brightly. If they burn up completely, they are meteors. If remnants land on the Earth, they are meteorites
Where? in thermosphere, 80-120 km high
How Big? small pebble down to grain of sand, < 1-2 grams
How fast? 11-72 km/s!
How many? quite variable: depends on a lot of factors ...
Leonid Meteor Storm 2001
Fireballs!
Fireball Movie
fireball_animated.gif
Major Meteor Showers:
QUADRANTIDS: Jan 3 (Jan 1-5), up to 100/hr
LYRIDS: April 22 (April 16-25), 10-20/hr
ETA AQUARIDS: May 6 (Apr 18-May 28), ~20/hr
SOUTH DELTA AQUARIDS: Jul 29, up to 20/hr
PERSEIDS: Aug 12 (from 10pm), tens/hr **DARK**
ORIONIDS: Oct 21 (Oct 20-22), 20-25/hr **SOME MOON**
LEONIDS: Nov 17 (Nov 14-21), 5-15/hr ?? **SOME MOON*
GEMINIDS: Dec 14 (Dec 7-17), ~35/hr **FAIRLY DARK**
The Perseids
The Perseids
Comet Swift-Tuttle
1862, 1992, 2126
The Perseids
The Perseids: Where in the Sky?
How to Observe Meteor Showers
Look online or in astronomy magazines (e.g. Sky &
Telescope, SkyNews) for dates, sky charts, etcFind where the shower radiant is
Find a dark place where you can see the whole sky. Try
to avoid the Moon. Dress warmly. Give yourself time for your eyes to get dark-adapted You don't need binoculars or telescopes-- just your eyes! Sit in a chair or lie on the ground. Look about 30
degrees away from the shower radiant You'll see more meteors the later you stay up--
especially after midnight
Meteor Shower from Space
Some WWW Pages
http://spaceweather3.com/
http://skytour.homestead.com/met2006.html
http://www.space.com/spacewatch/060804_night_sky.html
http://www.amsmeteors.org/
http://www.amsmeteors.org/faqm.html
http://comets.amsmeteors.org/
http://csep10.phys.utk.edu/astr161/lect/meteors/showers.html
Monitoring of Near-Earth Objects (NEOs)
NASA estimates there are 1100-1200 NEOs 1km or larger in
size, with 1 in 500,000 chance of impact with Earth in next 100 yr
Similarly, estimates of ~500,000 NEOs with diameters between
50-100m; still large enough to cause considerable damage. 1
chance in 1000 of impact with Earth in next 100 yrs
Lots of NEO monitoring going on now, using small 1-2 m
telescopes (e.g. Spacewatch)
But what could we do if we found a big one on a collision
course?? Deep Impact will give some information ...
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