Across
- 3. white ____: the remains once a medium or small star has died
- 4. force that keeps objects with mass attracted to each other
- 8. ____ year: common measurement of distance in astronomy
- 10. man-made orbitter of a planet
- 11. group of galaxies bound together by gravity
- 13. celestial body that orbits a planet
- 15. dark ____: hypothetical force responsible for the universe's accelerating expansion
- 19. cloud of gas and dust in space
- 20. orange ____: a medium or small star when it is aging
- 22. universe's ongoing process of getting bigger
- 23. celestial body that emits light and heat
Down
- 1. path a planet takes around its star
- 2. big ____: theory that explains the origin of the universe
- 5. HR _____: graph used to classify stars based on temperature and brightness
- 6. _____ star: the remains once a huge star has died
- 7. ____ dwarf: a medium or small star that is no longer emitting light
- 9. black ___: region in space with such strong gravity that nothing can escape it
- 12. main _____: stage in a star's life when it fuses hydrogen into helium
- 14. most abundant element in the universe
- 16. vast collection of stars, gas, and dust
- 17. celestial body that orbits a star
- 18. process that powers stars by combining hydrogen atoms
- 19. super ____: massive explosion in space
- 21. ____ matter: mysterious substance that makes up most of the universe's mass
- 23. red ____ giant: a huge star when it is aging