Solar System

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Across
  1. 2. This force pulls down and the strength depends on the mass of an object.
  2. 4. This is our main natural light source.
  3. 6. This is the farthest planet discovered by unaided human eye.
  4. 9. This planet is the oldest forming 4.5 billion years ago.
Down
  1. 1. This is our space neighbor hood, with 8 planets and 1 star.
  2. 3. The atmosphere is so dense the sun looks like a smear of light.
  3. 5. This planet’s tilt is 97.7 degrees.
  4. 7. This is the only planet not named after a Greek God.
  5. 8. This planet is the most researched by scientists.