Across
- 1. what the universe is full of
- 4. planets moving towards us
- 5. system of millions or billions of stars
- 8. expansion
- 9. One of the first elements
Down
- 2. microwave radiation
- 3. person who originated the theory of the
- 6. One of the first elements
- 7. planets moving away
- 8. all existing matter
