Across
- 5. visible to the human eye
- 6. celestial objects
- 7. space studies
- 9. flammable+gas
- 10. genius
- 12. needed
- 13. radiation
- 15. found small amount of something
- 16. galaxies
- 17. length of radiation
Down
- 1. measure light
- 2. stars and matter
- 3. how light shifts
- 4. space and time
- 8. theater
- 11. how our universe started
- 14. inert-gas