Across
- 3. the planet we live on
- 6. move in a circle
- 9. the outside layer
- 11. a thought
- 12. an free area or room
- 13. a luminous point in the sky
- 14. a region of the solar system beyond Neptune
- 16. earths natural satellite
- 19. the action of rotation
- 20. the extremely hot center of earth
Down
- 1. the distance from north to south
- 2. the length of a line from each edge
- 4. a place where something has been placed
- 5. the force that attracts two together
- 7. an invisible line that an object rotates on
- 8. an icy small planet
- 10. pieces of rock floating space
- 12. a set of things
- 15. an evolution of revolving
- 17. the curved path of a spacecraft
- 18. the biggest star