Across
- 4. fusion of H2 and He
- 6. bright center of a distant galaxy
- 8. full of old stars
- 13. squeezing atoms together
- 14. tells us galaxies are moving away
- 15. hottest layer of atmosphere
- 18. young stars in the arms
Down
- 1. loop of gas
- 2. wild patterns of stars
- 3. collapsed neutron star no light escapes
- 5. cloud of gas and dust
- 7. a collapsed core of a high mass star
- 9. 1 trillion miles
- 10. the raisins spread apart as bread rises
- 11. cooler areas on surface
- 12. start of expansion
- 15. warm rises, cool sinks
- 16. stream of charged particles
- 17. apparent shift