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Meteor Showers

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  1. Meteor Showers

  2. What's the Source of Meteor Showers? Comets ...

  3. ... and Asteroids!

  4. Nucleus of Comet Halley from the Giotto Probe

  5. How It Works ... Meteor Shower Movie Comet Movie

  6. 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 ...

  7. Leonid Meteor Storm 2001

  8. Fireballs! Fireball Movie fireball_animated.gif

  9. 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**

  10. The Perseids

  11. The Perseids Comet Swift-Tuttle 1862, 1992, 2126

  12. The Perseids

  13. The Perseids: Where in the Sky?

  14. How to Observe Meteor Showers • Look online or in astronomy magazines (e.g. Sky & Telescope, SkyNews) for dates, sky charts, etc • Find 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

  15. Meteor Shower from Space

  16. 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

  17. 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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