Across
- 4. look like spheres or ovals and are thought to contain older stars
- 7. defined as space and all the matter and energy in it
- 8. the group of more than 20 galaxies
- 9. when gravity holds groups of galaxies together
- 12. a galaxy with a central bar-shaped structure composed of stars
Down
- 1. a Barred Spiral Galaxy containing about 200 billion stars and stretching about 100,000 light years across
- 2. the distance light travels through space in one year
- 3. large collections of stars, gas, and dust held together by gravity
- 5. no particular shape and are thought to contain newer stars
- 6. vast spaces between filaments, which contain very few or no galaxies
- 10. a group of galaxy clusters
- 11. new stars form near the arms