Across
- 2. how the universe started
- 5. huge explosion that occurs at the end of a very large star's life
- 7. distance light travels in on year
- 9. all that exists in space
Down
- 1. natural satellite that orbits a planet
- 3. layer of gas around the planet
- 4. collection of stars held together by gravity
- 6. large heavenly body which orbits around a star such as the sun
- 8. invisible line around the earth midway between the north pole and the south pole