1. Earth, Moon, & Sun SOL 4.7

2. an object that moves around another object in space

3. satellite

4. a huge burning sphere of gas

5. star

6. the path an object, such as a planet, makes as it revolves around a second object

7. orbit

8. a group of objects in space that move around a central star

9. solar system

10. The motion of a planet as it turns on its axis. This takes 24 hours to complete.

11. rotation

12. The movement of any object in orbit, such as Earth moving around the Sun, which takes 365 ¼ days to complete

13. revolution

14. an imaginary line which runs through both poles of a planet

15. axis

16. a large object that moves around a star

17. planet

18. the different shapes the moon seems to have as it orbits around Earth

19. phases

20. I was a Greek astronomer who believed in the Earth-centered model of the universe (Geocentric). This means I thought the Earth was the center of the universe! Boy was I wrong!

21. Aristotle

22. I was an Egyptian astronomer who believed in the Earth-centered model of the universe (Geocentric). This means I thought the Earth was the center of the universe! I was wrong!

23. Ptolemy

24. I was a Polish astronomer who challenged the Geocentric model of the universe. I introduced the Sun- centered model of the universe (Heliocentric). I believed the Sun was the center of the universe.

25. Copernicus

26. I was an Italian astronomer who believed the Sun-centered model of the universe (Heliocentric). I was even put in jail for a long time because of my belief!

27. Galileo