Across
- 3. A push or pull exerted on an object
- 5. Bang: The initial explosion that resulted in the formation of planets
- 6. Center of the sun
- 8. The partial or total blocking of one object in space by another
- 9. A place that is empty of all matter
- 10. The attractive force between objects
- 13. An object that orbits a star and is large enough to have become rounded by its own gravity, and has cleared the area of its orbit
- 14. Loose collection of dust and ice that orbits the sun
- 16. The movement of an object around another object
- 17. The tendency of an object to resist a change in motion unless acted on by an outside force
- 19. the periodic rise and fall of the level of water in the ocean
- 20. Amount of matter in an object
Down
- 1. A device that expels gas in one direction to move in the opposite direction
- 2. A measure of the force of gravity on an object
- 4. Huge group of single stars and star systems and star clusters and dust and gas held together by gravity
- 7. A building that contains one or more telescopes
- 11. A ball of hot gas that is primarily hydrogen and helium that undergoes nuclear fusion
- 12. A rocky object that revolves around the sun that are too small to be planets
- 15. The path of an object as it revolves around another object in space
- 18. An imaginary line that passes through a planet's center that the planet rotates on