solar system crossword

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Across
  1. 1. planet made of gas
  2. 7. not being harmful to the planet
  3. 8. planet with ice
  4. 9. solar system is in it
Down
  1. 2. there are eight planets in it
  2. 3. mass of air that surrounds planets
  3. 4. the outside part or uppermost layer of something
  4. 5. the force of an object to pull another to it
  5. 6. separates inner planets from outer planets