Across
- 4. closest galaxy to milkyway
- 6. looking far
- 7. strong gravity
- 9. sun
- 14. solid planets
- 15. largest moon
- 17. metal from space
- 19. very dense
- 20. big planet
Down
- 1. first light
- 2. explosion
- 3. rocks
- 5. other life
- 8. hot planet
- 10. distance
- 11. flying to space
- 12. dead star
- 13. atom
- 16. person
- 18. ice