Across
- 4. a powerful and luminous stellar explosion
- 6. piece of stony or metallic debris
- 8. Pluto was reclassified as this in 2006
- 10. giant a giant planet composed mainly of hydrogen and helium
- 12. the third planet for the sun
- 13. star at the center of the solar system
Down
- 1. orbiting the earth
- 2. hole nothing can escape this
- 3. Sun become after they have exhausted their nuclear fuel
- 5. containing billions of galaxy
- 7. a huge collection of gas, dust, and billions of stars and their solar systems
- 9. distance that light travels in one year
- 11. luminous ball of gas