Across
- 4. our galaxy is know as
- 8. connects the polar ocean waters
- 11. layer that protects us from UV
- 16. estimated number of galaxies
- 17. ocean used as a trade route between africa and asia
- 18. why stars shine
- 19. clumping smaller particles into larger masses
- 20. continent of south pole
- 22. discovered red shift
- 23. Early steps of organisms forming from organic building blocks
- 25. oldest rocks found in austalia
- 29. the largest ocean
- 31. are aggregations of gas and dust which may be several hundred kilometers in diameter
- 33. percentage that the Atlantic covers earth
Down
- 1. huge rotating aggregations of stars, dust, and gas held together by gravity
- 2. a theory on beginning of univerese
- 3. years the accretion period lasts
- 5. how old are the oldest fossils
- 6. the star that gives earth heat
- 7. includes all the countries south of panama
- 9. percent of ice that covers earth
- 10. a super nova explosion is also known as
- 12. the sun is what kind of star
- 13. smallest continent
- 14. release of volatile substances and water vapor
- 15. theory on how stars and planets were formed
- 21. Star’s core will eventually collapse in an explosion
- 24. person who experimented in 1953
- 26. suggested that heat energy from thermal vents in the sea could have formed into complex molecules of life
- 27. amount of years it took for rain to eventually form oceans
- 28. the first surface formed how many years ago
- 30. the smallest ocean
- 32. massive spheres of incandescent gas