Earth's Place in the Universe

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Across
  1. 2. Earth's most common gas
  2. 4. "Helio" and "Solar" both mean relating to the _______
  3. 7. The third planet from the sun
  4. 9. Planets that have a rocky crust
  5. 10. To move in a circle like fashion around the sun
  6. 12. An astronomer who disagreed with the Geocentric Model of Earth
  7. 13. Our home galaxy
Down
  1. 1. An image created by stars in the night sky
  2. 3. Jupiter, Saturn, Neptune, Uranus are all...
  3. 5. Asteroids, comets, planets and moons are all considered...
  4. 6. An imaginary line around which an object spins
  5. 8. For a planet to spin on it's axis
  6. 11. This is located at the center of the galaxy