Across
- 6. rotating "galaxy"
- 9. "It includes all of space and all the matter and energy that space contains"
- 10. Theory
- 11. When something falls it is because of
- 12. A cloud of gas and dust in space
- 13. Millions of planets and suns
- 14. A very well-known Galaxy
- 15. Have shapes that range from round to oval
Down
- 1. Something with infinite density
- 2. measures distances within the Solar System
- 3. Proof
- 4. Standard units of meusurments
- 5. The sun and the planets around it
- 7. The explosion of a large star
- 8. The speed at which light travels