1. Ch 9 Earth and Space By R. Aldridge

2. sun the star at the center of our solar system

3. rotate To spin on an axis

4. axis an imaginary line that passes through Earths center and its North and South Poles

5. revolve To travel in a closed path

6. orbit the path one body takes in space as it revolves around another body

7. equator an imaginary line around Earth, equally distant from the North and South Poles

8. moon any natural body that revolves around a planet

9. crater a bowl- shaped, low area on the surface of a planet or moon

10. moon phase one of the shapes the moon seems to have as it orbits Earth

11. eclipse an event occurs when one object in space passes through the shadow of another object in space

12. refraction the bending of light as it moves from one material to another

13. star a huge ball of very hot gases in space

14. solar system A star and all the planets and other objects that revolve around it

15. constellation a pattern of stars, named after a mythological or religious figure, an object, or an animal

16. planet a body that revolves around a star

17. universe everything that exists, including such things as stars, planets, gas, dust, and energy

18. galaxy a grouping of gas, dust, and many stars, plus any objects that orbit those stars