Universe Puzzle

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Across
  1. 2. a tool used to observe the universe
  2. 3. a rock that enters the atmosphere
  3. 6. EM radiation we can see
  4. 8. the brightness of a star
  5. 12. not even light can escape it
  6. 13. a body made mostly of ice
  7. 14. energy
  8. 15. the process that produces energy in a star
  9. 17. a chart that classifies the stars
  10. 18. a rocky body orbiting a star
  11. 21. the distance between two waves
  12. 22. EM radiation with the highest frequency
  13. 23. a rounded body orbiting a star
  14. 24. how hot a star is
  15. 25. a small hot star
Down
  1. 1. a collection of stars and other objects held together by gravity
  2. 4. a squashed oval shape
  3. 5. the rate at which an event occurs
  4. 7. when a super red giant implodes
  5. 9. a giant cloud of gas and dust
  6. 10. a rounded body that orbits a planet
  7. 11. when spectral lines are moved to longer wavelengths
  8. 16. EM radiation with the longest wavelength
  9. 19. a large cool old star
  10. 20. used to find the elements present in a star