Comets small body of ice, rock, and cosmic dust “dirty snowballs” tail visible when comet gets close enough to the sun (points away from sun due to solar winds) --tail can be millions of miles long gets smaller with every trip (melts)

…website animation… http://www.classzone.com/books/earth_science/terc/content/visualizations/es2706/es2706page01.cfm?chapter_no=visualization (comet passage)

You can see a comet for weeks (or months)! …unlike a meteor

Asteroids dense, rocky bodies that orbit the sun (over 100,000 known)—smaller than a planet most are irregularly shaped (not round) size: few meters to 900 km most found in the asteroid belt (between Mars and Jupiter)

Ceres largest known asteroid (785 km long)—now considered to be a dwarf planet

Meteoroids Meteoroid= small pieces of comets or asteroids in space Meteor= burning up in atmosphere (inaccurate to say “falling/shooting star”) Meteorite= hits the ground (MAY make a crater)

WOW!!! Meteor shower over Russia, Feb 15, 2013 http://www.youtube.com/watch?v=dBvotWfR3j4

Which one is this? What caused this? meteor meteorite

Did you know?? The mass of the earth increases every year because of the 3,000 TONS of meteorite debris that hits the surface from space! Approximately every 50-60 years, somebody is struck by a meteor; last time was in 1954 The odds of you being hit is a billion to one (no human has ever been killed by a meteor strike).

Think about it…. If we were to send a manned mission to Mars, how could we avoid getting damaged by the asteroid belt? The asteroid belt is between Mars and Jupiter. If you lived on the moon, about how many meteors would you see on the moon in an earth year? None—no atmosphere

Which of the following is a characteristic of comets? A. Comets are composed of rocky material, iron, and nickel. B. Comets follow a circular orbit around the sun. C. Comets give off gas and dust when heated by the sun. D. Comets are rich in iron.

Which of the following is a wide region of small, rocky bodies that is located between the orbits of Mars and Jupiter? A. the Kuiper belt B. the Oort cloud C. the asteroid belt D. the rings of Saturn

When it approaches the sun, which object produces a shimmering tail that lasts at least a few days? a comet In which direction does a comet’s tail always face? away from the sun

Where are most asteroids found? in orbit between Mars and Jupiter What is the sequence that describes a space rock that falls to Earth’s surface? meteoroid, meteor, meteorite

Which one of the following objects in our solar system would travel the greatest distance during one revolution around the sun? A. a terrestrial planet B. an asteroid C. a gas giant D. a comet