Science Cross Word

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Across
  1. 2. a group of a star and planets that surround it
  2. 4. when a galaxy is moving away
  3. 6. The theory matter was made by a small point
  4. 8. all stars and planets in a group
Down
  1. 1. a form of energy that propagates as both electrical and magnetic waves traveling in packets of energy called photons
  2. 3. the distance light makes in a year
  3. 5. giant cloud of dust and gas in space
  4. 7. the force that pulls all matter in
  5. 8. atoms making a substance that has no density