Science Crossword puzzle

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Across
  1. 5. a forcible overthrow of a government or social order, in favor of a new system.
  2. 8. the section of the Earth that is north of the Equator
  3. 10. the biggest star in our solar system
  4. 12. 30 days =
  5. 14. a triple star
  6. 15. a system of lines used to describe the location of any place on Earth
  7. 17. the opposite way the clock is going
  8. 20. 24 hours = ?
Down
  1. 1. A closed curve, consisting of all points whose distances from each of two fixed points (foci) add up to the same value
  2. 2. Temperature is the amount of heat in something. It's measured with a thermometer
  3. 3. a wrong or mistaken idea
  4. 4. is when something turns or spins around a point located at its center
  5. 6. when its dark outside its...
  6. 7. 12 months = ?
  7. 9. the area of Earth that is south of the Equator
  8. 11. Earth's ____ is 23.5 degrees
  9. 13. the time or date (twice each year) at which the sun reaches its maximum or minimum declination, marked by the longest and shortest days (about June 21 and December 22).
  10. 16. the star that stays in one place
  11. 18. the line going horizontally through the Earth
  12. 19. the time or date (twice each year) at which the sun crosses the celestial equator, when day and night are of approximately equal length (about September 22 and March 20).