SPACE

123456789101112131415161718
Across
  1. 2. Red planet
  2. 4. Twinkling celestial object
  3. 6. Center of our solar system
  4. 7. Vehicle that travels to space
  5. 10. Cloud of gas and dust in space
  6. 12. Earth's natural satellite
  7. 14. Artificial object in orbit around a planet
  8. 15. Prominent constellation
  9. 16. Second planet from the sun
  10. 17. Huge collection of stars
  11. 18. Largest planet in our solar system
Down
  1. 1. Planet with rings
  2. 3. Rocky object orbiting the sun
  3. 5. Person who explores space
  4. 8. Spacecraft for launching and landing
  5. 9. Optical instrument for stargazing
  6. 11. Icy object with a tail
  7. 12. Closest planet to the sun
  8. 13. Unidentified flying object
  9. 17. Force that keeps objects grounded