Across
- 1. variable you measure
- 3. only known planet with life
- 4. center of solar system
- 6. largest planet
- 7. ore burned for energy
- 9. once considered a planet
- 13. most abundant gas in atmosphere
- 15. planet with rings
- 19. definite shape and volume
- 20. energy in motion
Down
- 2. energy not in motion
- 5. earth sister planet
- 8. smallest thing
- 10. seventh planet
- 11. takes shape of what its contained in
- 12. first person on the moon
- 14. force that pulls
- 16. second person on the moon
- 17. first animal sent to space
- 18. closest planet to sun, warmest