Space Crossword

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Across
  1. 1. Known as the red planet.
  2. 2. The largest planet.
  3. 3. The hottest planet.
  4. 5. The force that keeps the planets in orbit.
  5. 6. The coldest planet.
  6. 8. Used to travel to the moon.
Down
  1. 1. The closest planet to the Sun.
  2. 4. The third planet from the Sun.
  3. 5. A vast collection of stars.
  4. 7. Earth's only natural satellite.