Across
- 2. What planet is believed to once have had a magnetic field that disappeared when the plants iron cooled
- 5. what type of object can give us information about the conditions in which the solid planets formed
- 6. the first known organism on earth most probably originated in
- 9. Explosion of a star
- 10. The name of the small early planets
- 13. earths iron core creates a magnetic field which protects the planet from
- 14. _______Stratifiction is responsible for the formation of the earths gravitational field
Down
- 1. Early steps orgsnisms forming from organic building blocks
- 3. what are scientist trying to determine when they look at the crust of the age of zircons
- 4. in 6 billion years the sun will hypothetical turn into ______
- 7. Clears so the sun can penetrate
- 8. whats a possible source of the water on the earths surface today
- 11. ______ of the clouds made heavy rains fall
- 12. way our galaxy is known as the ___