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D - Science - Ch 16
Comets, Asteroids & Meteors
Question | Answer |
---|---|
Where do comets originate? | Kuiper belt and Oort cloud |
Where do asteroids originate? | leftover pieces of the early solar system, mostly found between the orbits of Mars and Jupiter |
Where do meteoroids originate? | comets or asteroids |
What size are comets? | about as large as a mountain, excluding the tail |
What size are asteroids? | 3 are more than 300 km across, but most are less than 1 km in diameter |
What size are meteoroids? | smaller than comets or asteroids |
What is the composition of a comet? | ice, dust, or small rocky particles |
What is the composition of an asteroid? | rock |
What is the composition of a meteoroid? | rock or dust |
What are comets? | loose collections of ice, dust, and small rocky particles with orbits that are usually very long, narrow ellipses |
What are the three main parts of a comet? | nucleus, coma & tail |
What forms a comet’s tail? | gas and dust |
How long can a comet's tail be? | more than 100 million kilometers long |
What are asteroids? | rocky objects revolving around the sun that are too small and too numerous to be called planets |
Where is the asteroid belt? | lies between the orbits of Mars and Jupiter |
What happened when one or more asteroids collided with Earth about 65 million years ago? | the atmosphere was filled with dust and smoke, which blocked out sunlight around the world and scientists hypothesize that many species of organisms, including the dinosaurs, became extinct |
What is a meteoroid? | a chunk of rock or dust in space |
What is a meteor? | a streak of light caused by the burning up of a meteoroid in the atmosphere |
What is a meteorite? | a meteoroid that has passed through the atmosphere and hit Earth’s surface |
Where do meteoroids come from? | usually come from comets or asteroids |
What caused the craters on the moon? | the impact of meteoroids |