Sections Review

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Vocabulary

Review Questions

1. Where are most of the asteroids found?
2. Why are spacecraft able to pass through the asteroid belt without getting hit?
3. What are the three types of asteroids and what are they made of?
4. Why are more meteors seen after midnight?
5. What are the proportions of the three types of meteorites and what are they made of?
6. What type of asteroid does each type of meteorite correspond to?
7. Which meteorites are primitive and why are they particularly important for understanding the origin of the planets?
8. What makes carbonaceous meteorites so special?
9. Why are chondrules especially important for solar system formation models? What type of meteorite are they likely to be found in?
10. How old are the various types of meteorites and why are they used to find the age of the solar system?
11. Why do iron meteorites make up 40% of the ``finds'', but are only 2 to 3% of the total meteorites? What causes the biasing of the ``finds''?
12. Why is Antarctica a good place to get an unbiased sample of meteorites?
13. What makes SNC meteorites so unique and how are they different than other types of meteorites?
14. Why are iron and stoney-iron meteorites thought to come from a differentiated body?
15. Does radioactive dating give us relative or absolute ages for rocks? What type of ``age'' does it tell us?
16. How do you use the half-life to find the age of radioactive rocks?
17. If the half-life of a radioactive sample is 1 month, is a sample of it completely decayed after 2 months? If not, how much is left?
18. Uranium-235 has a half-life of 700 million years. How long will you have to wait until a 1-kilogram chunk decays so that only 0.0625 kilograms (1/16 kg) is left?
19. How are the very old ages derived for some radioactive rocks known to be correct?
20. If a large asteroid were to hit Earth, how much of the Earth's surface would be affected?
21. What would be the effects on Earth of an impact by an asteroid a kilometer or larger in diameter?
22. What are the current and proposed future programs to search for Near-Earth Objects?
23. What are possible ways of effectively preventing an asteroid impact with Earth?

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last updated: March 25, 2013