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 ...