Across
- 3. representing the earth as the center of the galaxy
- 6. the part of Earth's surface that is rock
- 7. heat produced from within the earth
- 9. a type of cloud that produces rain
- 11. existing below the earth's surface
- 14. the study of earthquakes
- 16. someone who studies ancient life
- 17. someone who travels to outer space
- 18. a line on a weather map that connects places with equal heat
- 19. without life
Down
- 1. the layer of gas surrounding the earth
- 2. the study of ancient human cultures
- 4. a device used to measure the angle of a slope
- 5. a portable device used to measure time
- 7. the study of ice
- 8. the layer of the earth where life can exist
- 10. happening at night
- 12. when the length of night is equal to the length of day
- 13. representing the sun as the center of the galaxy
- 15. someone who studies volcanoes