Across
- 3. theory the the solar system formed from cloud of gas
- 4. contains all life on earth
- 8. middle layer of the Earth
- 11. 0 degree latitude line, divides the earth north and south
- 12. this type of map shows elevation
- 14. inner layer of the Earth
- 15. thin gaseous envelope that surrounds the earth
- 17. study of the universe
- 18. well established highly reliable explanation
- 20. all water that makes up the earth
Down
- 1. outer layer of the Earth
- 2. an example of a constructive force
- 5. type of resource that can be renewed relatively shortly
- 6. any resource obtained from the earth
- 7. explanation of observation that can be tested
- 9. study of the Earth
- 10. study of the oceans
- 13. a type of system where energy flows in and out
- 16. powers the atmosphere and hydrosphere
- 19. this type of map shows direction accurately