Across
- 1. Star systems that have two stars.
- 5. The theory that the universe was formed in an instant in an enormous explosion.
- 6. The earliest stage of a star's life.
- 7. A large cloud of gas and dust that is spread out in an immense volume.
- 9. A system in which one star occasionally blocks the light from another.
- 10. A huge group of single stars, star systems, star clusters, dust and gas bound together by gravity.
- 12. Imaginary patterns of a group of stars forming pictures of people or animals.
- 13. Active young galaxies with giant black holes at their centers.
- 16. The mass that we cannot see in galaxies.
- 18. A unit of measurement used to measure distance between the stars.
- 19. The force that is causing the expansion of the universe to accelerate.
- 20. Galaxies that do not have regular shapes.
- 21. Galaxies that look like round or flattened balls with no gas or dust between stars.
Down
- 2. A star's brightness as seen from Earth.
- 3. The galaxy that our solar system is located in.
- 4. The brightness a star would have if it were at a standard distance from Earth.
- 8. An object with gravity so strong that nothing, not even light, can escape.
- 11. Larger groups of stars.
- 14. A device that breaks light into colors and produces an image of the resulting spectrum.
- 15. Galaxies with a lump in the middle and arms spiraling outward.
- 17. The apparent change in position of an object when you look at it from different places.