Across
- 3. A region of space containing a collection of asteroids or objects
- 6. Material thrown out by an impact event like a crater formation
- 7. A large planet composed mostly of hydrogen and helium
- 9. The apparent backward movement of a planet in the sky
- 11. When a celestial body keeps the same face toward another
- 12. The average distance between Earth and the Sun
- 14. A meteoroid that survives its passage through Earth's atmosphere
- 17. When the Sun reaches its highest or lowest point in the sky
- 18. A celestial object made of ice and dust with a glowing tail
- 19. A rocky planet with a solid surface, like Earth
Down
- 1. The imaginary plane in which most planets orbit the Sun
- 2. A region beyond Neptune that contains icy bodies
- 4. The time when day and night are of equal length
- 5. A celestial body too small to clear its orbit of debris
- 8. A small rocky or metallic body traveling through space
- 10. Large, dark basaltic plains on the Moon caused by lava flow
- 13. When the Earth blocks sunlight from reaching the Moon
- 15. An elongated circle that represents planetary orbits
- 16. A measure of how an orbit deviates from a perfect circle