Across
- 2. a heavy electron.
- 3. a big things that went around a sun and moons were anything that went around.
- 6. a generic name for electrons and their relatives.
- 7. hole a star that crush with great gravity.
- 9. it was invented to Save the conservation of energy.
- 10. something can can never be prove___________?
- 11. science consist of Scientific theory and ____________?
- 15. a no longer consider planet.
- 16. closest planet to the sun.
- 17. dark matter, star, and what make up a galaxies.
- 19. Cloud comets froze a huge spherical cloud far outside of the Kuiper belt.
Down
- 1. system consist of things that go around a Star.
- 3. neutron and ______ are help together by mesons?
- 4. Quarks are held together by what?
- 5. a group of millions to billions of stars help together by mutual gravity.
- 8. result from a runaway thermonuclear reaction.
- 12. what is the opposite charge of a proton?
- 13. rocks going around space.
- 14. something lots smaller than atom.
- 18. big enough to get hot.