Space

3. A group of stars, gas and dust held together by gravity. Starts with a G.
4. A rock, or Minor Planet orbiting the Sun. It sometimes hits planets such as earth.
5. The path one object takes around another.
8. The point directly above your head in the night sky (starts with Z)
11. The biggest planet in our solar system out of the eight planets other than the sun!
14. The faint glow of the moon when the side facing Earth is dark. Caused by light reflecting off the Earth.
17. An instrument that aids in the observation of things that are far away.
18. A shooting star, observed when a particle of dust enters into the Earth's atmosphere.

1. Amount of time it takes the Earth to spin once on its axis.
2. Negative particle which orbits an atom.
4. The gaseous area surrounding a planet or other body.
6. It was a small planet, but it's not a planet anymore.
7. The planet with the ring
9. When our view of one object in the sky is blocked by either another object or the Earth's shadow.
10. The natural glow of the night sky due to reactions that take place in the Earth's upper atmosphere.
12. The densest planet in the solar system
13. Something we see in the nigh sky (sometimes) other times it is hidden by clouds. Sometimes it is full or partially full. It reflects light off the sun.
15. A giant 'fireball'.
16. Something we see in the night sky. They twinkle.
18. The second smallest planet in the solar system.