Across
- 7. explosion of a star
- 9. Ice covers about ___ of earth
- 11. a very large star of high luminosity and low surface temperature
- 13. a cloud of gas and dust in outer space that is visible in the night sky
- 15. what color penetrates the ocean the best
- 16. North American doesn’t include
- 17. covers 20.8% of earth
- 19. a fixed reference line for the measurement of coordinates
- 20. smallest,coldest, and is known as the Northern Sea.
- 22. an imaginary line through the pacific ocean
- 25. lasted 50-70 million years
- 28. continent of the south pole
Down
- 1. first organisms on earth that appeared almost 4 billion years ago
- 2. what is responsible for the formation of Earth’s gravitational pull
- 3. most accurate representation of the features of earth
- 4. Planets solidified in a process known as
- 5. is a star
- 6. covers 30.5% of earth
- 8. action of observing or finding one’s way by using the moon, sun, and stars
- 10. connects polar waters
- 12. the reason why stars twinkle
- 14. The tallest mountain in the world
- 18. North America includes ____, Mexico, & Canada
- 21. a unit of speed equal to 1 nautical mile
- 23. a unit of distance , set by international agreement
- 24. fell for 10 million years
- 26. release of gas or vapor
- 27. the name of our galaxy