Space

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Across
  1. 4. The planet most similar in size to Earth
  2. 6. A cloud of dust and gas in space
  3. 9. The name for the study of the origin and structure of the universe
  4. 10. The name of our galaxy
  5. 11. The name of the path a planet takes around a star
  6. 12. The largest planet in the solar system
  7. 13. A small rocky object orbiting a star
  8. 15. An object that orbits a planet
  9. 17. The closest star to Earth
  10. 18. The name of the force that holds the solar system together
Down
  1. 1. A small icy object that orbits a star
  2. 2. The process a star uses to produce energy
  3. 3. The closest planet to the Sun
  4. 5. A region of space with gravity so strong not even light can escape
  5. 7. The name of the man-made object that has travelled furthest into space (no number)
  6. 8. The number of planets in the solar system
  7. 14. Caused by the explosive death of a massive star
  8. 16. the distance light travels in one year