Across
- 3. earth's position from the sun
- 5. a person trained to travel in space
- 10. protective wear for astronauts
- 11. star explosion
- 12. our galaxy
- 14. popular term for alien spacecraft
- 16. farthest planet from the sun
- 18. planet with 274 moons
- 20. measure of stars brightness
- 21. layers of gases around a planet
- 22. first American in orbit
- 24. outermost layer of the sun
Down
- 1. NASA's rover on mars
- 2. primary gas that fuels stars
- 4. frozen bodies with tails
- 6. first man on the moon
- 7. a dead star's remnant
- 8. planet with prominent rings
- 9. the largest planet in our solar system
- 13. greek god after which mars is named
- 15. largest moon in our solar system
- 17. telescope launched in 1990
- 19. planet known for extreme winds
- 23. president during Apollo 11