Galactic quiz

123456789101112131415
Across
  1. 3. once a piece of Earth
  2. 5. the space is silent due to lack of
  3. 7. Comet that'll next appear in 2061
  4. 9. 99% of mass of our solar system is
  5. 12. our galaxy's black hole
  6. 14. A failed star
  7. 15. stars that spin 600 times per second
Down
  1. 1. closest star to us
  2. 2. most reflective body in our solar system
  3. 4. number of dwarf planets in our solar system
  4. 6. the planet that rotates in opposite direction to Earth
  5. 8. the spherical cloud in which boundary of our solar system ends
  6. 10. planet made of diamonds
  7. 11. blue sunsets happen in
  8. 13. orbits sun on its side