Across
- 3. The measure of how much light a surface reflects.
- 4. An event in which one celestial body blocks the light of another.
- 6. Despite its name, it measures distance rather than time.
- 9. The time of year when day and night are nearly equal.
- 11. The bright streak seen when a space rock burns in Earth's atmosphere.
- 12. A rocky object that mostly orbits between Mars and Jupiter.
- 14. The process that powers the Sun by combining atomic nuclei.
- 15. The force that keeps planets moving around the Sun.
- 16. The longest or shortest day of the year.
- 18. A natural or artificial object that revolves around a planet.
- 19. The path followed by a planet or satellite around another object.
Down
- 1. A system containing billions of stars, gas, and dust.
- 2. The spinning of a planet on its axis.
- 5. A bowl-shaped depression formed by an impact on a planetary surface.
- 7. A recognized pattern of stars in the night sky.
- 8. One complete journey of a planet around the Sun.
- 10. A cloud of gas and dust where new stars can form.
- 11. A space rock that survives its journey through Earth's atmosphere and reaches the ground.
- 13. An instrument that collects light to observe distant objects.
- 17. The point in the sky directly above an observer.