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