1. Handout 3 (1-2) Chpater’s 28-4 and 30-3 Asteroids, Comets, and Meteroroids And Star Groups

2. Handout 28-4 Asteroids, Comets, and Meteoroids

3. 1. In addition to the sun, planets, and their moons, what occupies the space in our solar system? The solar system includes million of smaller bodies; some are tiny bits of dust or ice; others are as large as small moons.

4. 2. What are asteroids? fragments of rock that orbit the sun

5. 3. Most asteroids are found in the asteroid belt located between the orbits of Mars and Jupiter.

6. 4. The composition of asteroids is similar to that of the inner planets.

7. 5. For what reason do many astronomers think that asteroids in the asteroid belt were not able to form a planet? because of the strong gravitational force of Jupiter

8. 6. What is a comet? a small body of ice, rock, and cosmic dust that orbits the sun

9. 7. A comet’s spectacular tail forms when sunlight changes the comet’s ice to gas.

10. Matching 8-13 8.meteora.a large number of meteoroids entering Earth’s atmosphere in a short period of time. 9.meteor showerb.a bright streak of light that results when a meteoroid burns up in Earth’s atmosphere 10. iron meteoritec.a meteorite similar in composition to rocks on Earth that may contain carbon compounds 11. stony meteorited.the rarest type of meteorite 12. meteoritee.a meteoroid or any part of a meteoroid that is left when it hits Earth 13. stony-iron meteoritef.a meteorite with a distinctive metallic appearance

11. Types of Meteorites

12. Fifty thousand years ago, a giant fireball streaked across the North American sky. It struck the earth in what is now northern Arizona, exploding with the force of 2 ½ million tons of TNT.

13. 14. Why are the oldest meteorites important? Because they may be 100 million years older than Earth and its moon, and thus may provide information about how the early solar system formed.

14. Handout 30-3 Star Groups

15. 1. What is a galaxy? a large-scale group of stars, gas, and dust bound together by gravity

16. 2. What is the diameter of the Milky Way? about 100,000 light-years

17. 3-6 Matching 3.elliptical galaxy a.varies from almost spherical to a stretched out football in shape and has a bright center 4.barred spiral galaxy b.has a nucleus of bright stars and flattened arms that circle around the nucleus 5.irregular galaxy c.has a no particular shape and may have a low total mass 6.spiral galaxyd.has a straight bar of stars that runs through the center

18. Types of Galaxies

19. 7. What does the Milky Way look like in the night sky? a cloudlike band that stretches across the sky

20. 8. How is the sun related to the Milky Way? It is one of hundreds of billions of stars in the Milky Way.

21. 9. How long does it take the sun to orbit around the Milky Way? About 225 million years

22. 10. What are the closest neighbors to the Milky Way? Two irregular galaxies called the Large Magellanic Cloud and the Small Magellanic Cloud

23. 11. How far from Earth are the Milky Way’s closest neighbors? More than 170,000 light-years away from earth

24. THE END???