Space

2. A creature from a different planet
4. The layer of gases that are around our planet
9. A special type of clothes you need to wear when you go into space
11. A person who travels into space
13. A planet that could propose to somebody because it already has got a ring
14. A piece of rock from space that has landed on Earth
16. A very hot star, it has got a long tail of small pieces that can be seen
17. The force that attracts objects towards one another, especially the force that makes things fall to the ground

1. Any planet's natural satellite
3. The planet we live on
5. The red planet
6. The Sun and the group of planets that move around it
7. The largest planet
8. The first dog that travelled into space
10. A hole in the surface of Earth made by something hitting the ground with force
12. We use it to see stars and planets
15. A vehicle used by astronauts to travel in space
16. A large group of stars