Across
- 4. they look like stars but have different wavelengths
- 8. spherical cloud of stars and star clusters
- 10. contain a thousand more galaxies
- 11. what astronomers use to say both the halo and central bulge
- 12. flattened cloud of billions of stars
- 13. how we identify the different galaxies
- 14. mass that is invisable
Down
- 1. forms from gravity
- 2. contains most of the stars, gasses, and dust
- 3. how we know the universe is expanding
- 5. are rich in metal
- 6. about 3300 light years
- 7. how we determine a galaxy's distance
- 9. when light passes a massive source of gravity it gets pulled
- 10. orbital velocity versus radius