Across
- 1. Fusion of H and He
- 3. loop of gas
- 7. hottest layer of atmosphere
- 10. squeezing atoms together
- 12. collapsed core of a high mass star
- 14. the raisins spread apart as the universe expands
- 15. apparent shift
- 16. 9 trillion miles
- 17. start of explosion
- 18. cloud of gas and dust
- 19. collapsed neutron star, no light escapes
Down
- 2. warm rises cool sinks
- 4. all old
- 5. stream of charged particles
- 6. tells us galaxies are moving away
- 8. cooler areas on surface
- 9. bright center of a distant galaxy
- 11. all new
- 13. new stars in arms, old in center