Across
- 2. Type of galaxy that contains old stars.
- 5. A super-powerful explosion of a star.
- 6. Our universe formed 13.8 ____ years ago.
- 8. A giant cloud of dust and gas.
- 9. all held together by gravity.
- 10. Type of galaxy that look like a pinwheel.
Down
- 1. How astronomers explain the way the universe began as a single
- 3. A huge collection of gas, dust and billions of stars and their solar
- 4. then expanded.
- 7. Type of galaxy with a non-uniform shape.