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Download Activity 4- Impact Events and the Earth System
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Activity 4- Impact Events and the Earth System Barringer Crater – Northern AZ • The world’s best preserved meteorite impact site on Earth. Meteor Crater is the breathtaking result of a collision between an asteroid traveling 26,000 miles per hour and planet Earth approximately 50,000 years ago. • Meteor Crater is nearly one mile across, 2.4 miles in circumference and more than 550 feet deep. • www.meteorcrater.com Asteroids • Rocky bodies left over from formation of the solar system • Orbit the sun – very eccentric orbits • Asteroids >1km hit the Earth every few hundred million years Asteroids • Ceres (the largest- 950 Km across) is classified as a dwarf planet • It is widely believed that an asteroid caused extinction of the dinosaurs • NASA is currently working on a mission to have an astronaut walk on an asteroid! NASA Near Earth Objects watch Torino Scale Measures the effects of an impact • Scale 1-10 • 1 = little effects • 10 = catastrophic effects Comets • Dirty snowball! Frozen gas and dust • Orbits are very eccentric and have a high inclination • Have two tails, the gas tail (blue) and the dust tail (white) • Famous periodic cometHalley’s Comet (July 28, 2061 next perihelion) Halley’s Comet • Passes by Earth every 75 years • Next approach July 28, 2061 – mark your calendars! • 10 miles long, 5 miles wide and 5 miles high Anatomy of a Comet • Tail always faces AWAY from the sun • Coma – cloud of dust and gas • Nucleus – center of the comet Meteoroids, Meteors, and Meteorites • Named for where they are: – A meteoroid is in space – A meteor is passing through the Earth’s atmosphere (shooting star) – A meteorite is found on Earth
