Across
- 1. leftover "heat" from the big bang.
- 4. a big reddish star late in its life cycle.
- 6. the stage after a nebula.
- 7. a group of 30 or more galaxies.
- 9. a big ball of gas that's orange and gives us light every day.
- 11. the distance light travels in one year.
- 14. he identified the first stars outside the milky way.
- 15. how a star gets energy.
Down
- 2. something you can't see without xrays.
- 3. gas and dust a star is formed from.
- 5. the stage after a white dwarf.
- 8. a huge sphere that emits light and other radiation.
- 10. it consists of all space, matter, and energy that exists, now, in the past, or in the future.
- 12. a collection of millions to billions of galaxies.
- 13. a big explosion of a star.