Across
- 3. The force that pulls objects toward each other.
- 5. When the moon is fully illuminated.
- 7. An instrument for observing distant objects.
- 8. Another term for the moon.
- 10. Rise and fall of sea levels.
- 13. The absence of sunlight.
- 14. Earth's natural satellite.
- 17. The gases surrounding a celestial body.
- 19. A scientist who studies celestial bodies.
- 20. The final frontier.
- 25. A famous physicist known for his laws of motion and gravity.
- 26. The red planet.
- 27. Our home planet.
- 28. When the moon appears to increase in size.
Down
- 1. The shape of the moon during some phases.
- 2. Another gas giant known for its rings.
- 4. The distant blue planet.
- 6. The seventh planet from the sun.
- 9. The first man to walk on the moon.
- 11. A gas giant in our solar system.
- 12. A bowl-shaped depression on the moon's surface.
- 14. Space rocks that burn up in our atmosphere.
- 15. One-fourth.
- 16. A famous space program that landed humans on the moon.
- 18. The path a celestial object takes around another object in space.
- 21. When the moon appears to decrease in size.
- 22. Related to the moon.
- 23. The side of a celestial body that's visible.
- 24. American space agency.
- 29. Fresh.