Across
- 2. A person who thought Earth was in the center of the universe
- 3. A star that emits light when it pulse
- 6. Middle of our solar system
- 10. Everything in existence. Stars, gases, galaxies, black holes etc
- 11. A nuclear reaction in stars to create hydrogen/helium
- 12. Gas Giants are considered...
- 15. An explosion of a high mass star
- 16. The planet we live on
- 17. A force that pulls one object to a bigger object
- 19. The process of becoming bigger
Down
- 1. A person who thought the sun was in the center of the universe
- 4. The total energy a star can radiate per second
- 5. Planets that do not pass the asteroid belt are...
- 6. Massive celestial body
- 7. A point with infinite density
- 8. A cloud of gas in a galaxy
- 9. The study of the universe
- 13. The emission of energy as electromagnetic waves
- 14. Earliest forms of matter, 1e-16 meters
- 18. Any physical substance