Across
- 2. spherical region that surrounds the Milky Way's nuclear bulge and disk
- 3. theory says the universe is the same as its always been
- 6. gigantic threadlike clusters of galaxies
- 7. very bright and giant elliptical galaxy
- 9. says the universe is flat
- 10. theory that the universe began at a single point and has been expanding since
Down
- 1. weak radiation that is left over from early stages of big bang expansion
- 2. calculate the rate the universe is expanding
- 3. type of wave that creates spiral arms in a galaxy
- 4. has pulsation periods ranging from 1.5 hrs to 1 day
- 5. study of the universe
- 8. extremely distant objects with emission lines in their spectra