Across
- 1. The far side of the moon is not ________ to us.
- 9. The path around another planet or star
- 10. when a star explodes
- 11. to get smaller and smaller
- 14. You need a __________ to see that the milky way is made of millions of stars.
- 17. scientists that study stars
Down
- 2. The Big Bang happened 14 ________ years ago.
- 3. the most common substance in the Universe
- 4. anything that has mass
- 5. Neil Armstrong landed here.
- 6. The largest planet in our solar system
- 7. a thousand billion
- 8. The Red Planet
- 12. The Big Freeze
- 13. Its surface is covered in volcanic mountains and has almost no craters.
- 15. 6th planet from the sun
- 16. _________ on Earth is stronger than on Mars.