Astronomy and Space Science Crossword

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Across
  1. 2. huge group of single stars, star systems, etc. bound together by gravity
  2. 7. this model observed that the moon revolved around the earth
  3. 10. methane give this planet a blue green color
  4. 11. path around the sun
  5. 13. revolves around the Sun
  6. 14. debris left by colliding asteroids or dispersing comets
  7. 15. distance that light travels in one year
  8. 18. patterns of stars in the night sky
  9. 20. units measure distances among the objects int he solar system
Down
  1. 1. used to be a planet
  2. 2. this model thought planets, sun and moon revolved around the Earth
  3. 3. closest planet to the sun
  4. 4. extremely dense atmosphere
  5. 5. system born 4.6 billion years ago
  6. 6. planet with the great red spot
  7. 8. day when Earth's rotation axis is leaning along Earth's orbit, neither toward nor away from the sun
  8. 9. day when Earth's rotation axis is the most toward or away from the sun
  9. 12. the red planet
  10. 13. elongated closed curve
  11. 16. happens every 365.24 days
  12. 17. water exists on this planet
  13. 19. the nearest star to the Earth