Across
- 2. a method to test, revise, and conclude and idea
- 3. galaxies that can be round or oval
- 7. group of planets revolving
- 10. exploding star
- 11. a giant cloud of dust and gas
- 14. a force that keeps us on earth
- 15. is a unit based on a natural phenomenon
Down
- 1. something that supports or refutes a theory
- 4. a unit of measurmant equal to 149.6 million km
- 5. everything
- 6. nothing can escape its gravity
- 8. rotating disk with bulge
- 9. a collection of stars, clouds, and dust that we live in
- 12. distance light travels in a year
- 13. something that is made with stars, dust, and gas held with gracity