Across
- 6. big rock
- 7. explains known facts;
- 9. of gas that shines by radiation derived from its internal energy sources.
- 10. the hot center of earth
- 12. the outermost layer of a material or substance.
- 14. repeating path that one object in space takes around another one.
- 16. a straight line
- 17. the planet human beings and animals adapt and live on
- 19. a place where something been placed
- 20. hot glowing ball of hydrogen and helium
Down
- 1. icey small planet
- 2. measures the distance north or south of the equator.
- 3. a force
- 4. doughnut shaped ring of icy objects
- 5. Earth's only natural satellite.
- 8. a limited extent in one, two, or three dimensions
- 11. the circular motion of an object around its center.
- 12. group of interacting or interrelated elements that act according to a set of rules to form a unified whole.
- 13. the action by a celestial body of going round in an orbit or elliptical course.
- 15. the movement or path of the earth or a heavenly body turning on its axis.
- 18. imaginary line