Asteroids Comets Meteors and Impacts Asteroid belt rocks

Asteroids, Comets, Meteors and Impacts! ---- Asteroid belt -rocks orbiting sun- between Mars and Jupiter

Comets -- large chunks of frozen gases, water and solid particles From Kuiper belt and Oort Cloud in large elliptical orbits UV from Sun ionizes the frozen gases, and they fluoresce. Tail made up of glowing gases and solid particles that reflect sunlight.

Historically comets have been viewed as good and bad omens Halley’s comet 1911

Comet Wild 2 Hale-Bopp Composition: hydrogen, carbon & nitrogen compounds

Halley’s comet -- Sir Edmund Halley using Newton’s laws calculated orbit of comet of 1682, suggested it was same as previous comets and predicted return in 1758 (76 yr period) Giotto 1986

Meteor showers -- when Earth intersects debris from existing or extinct comet -- named for constellation the meteors appear to radiate Leonids – Nov. – Tempel-Tuttle Perseids – Aug – Swift-Tuttle

Meteors and Meteorites Meteor - Small solid particles (rocks) enter atmosphere everyday, most disintegrate, burn up due to friction they are seen as “shooting stars” Occasionally survive passage -meteorite

Some famous Meteorites

Barringer Crater The crater was created about 50, 000 years ago during the Pleistocene epoch on the Colorado Plateau

The bigger the strike the rarer the event. One event seems to have had a major effect. Lets look at 2 of these

1/. The K-T event -- 65 million years ago Chicxulb crater in Yucatan – 200 km diameter 10 km asteroid Caused 75% extinction 2/. Tunguska event 1908 in Siberia Small asteroid ~ only 40 m wide

Comet Shoemaker – Levy 9 (SL 9) 1994 impacts Jupiter

Summary • Asteriods = Rocks in orbit around the sun • Coments= large chunks of frozen water and solid particles in large elliptical orbits • Meteor = Rock hits the atmosphere • Meteorite = Lands on the earth

H/W • P 400 • Write a short piece or do a poster for your end of year ESI use one of the research projects