Across
- 2. 95 percent of the mass and energy contents in the universe are made of dark matter and this.
- 4. cosmic ______ background radiation; evidence that the big bang occurred
- 5. Hubble used this to measure galaxies, shows galaxies are moving away from us
- 9. the neighboring galaxy that is slightly larger in mass than us
- 11. Sagittarius A, the black hole at the center of our galaxy, releases these kind of waves
- 12. the invisible particles traveling freely through the universe and are extremely hard to detect
- 13. the invisible and mysterious component that makes up about 25% of all the mass in our universe
- 17. the type of galaxy we live in
Down
- 1. the name of our galaxy's arm that our sun is located in
- 3. once you cross this part of a black hole, nothing can escape; not even light
- 6. the most common type of galaxy in the universe
- 7. some spiral galaxies have this running across its center
- 8. the first element created after the big bang
- 10. our solar system is located about 3/5 of the way from the ___ of the milky way galaxy
- 14. 13.8 billion years = ___ of the universe
- 15. the name of our galaxy
- 16. the type of galaxy that contains mostly older stars