Across
- 1. One of this unit is the average distance between the Earth and Sun
- 3. The region at the edge of our Solar System filled with ice clumps
- 5. Hypothetical substance thought to make up most matter in the universe
- 7. Russian term for astronaut
- 10. Comet whose 1835 and 1910 appearances framed the birth and death of Mark Twain, fulfilling his famous prediction
- 11. The fourth planet in the Solar System
- 13. This man wears the biggest belt in the universe
Down
- 1. The first 'a' in NASA
- 2. Massive stellar explosion marking the death of certain stars
- 4. Our galaxy
- 6. Planet known for its extensive ring system
- 8. Rocky body that enters Earth’s atmosphere and may reach the surface
- 9. 100km above the surface of the Earth is the border of space, called the _____ Line
- 12. Planet famous for being sideways