Astronomy Extra Credit

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Across
  1. 2. The main tool of astronomers.
  2. 3. Law that states the greater the red-shift, the farther away an object is.
  3. 5. Planets do not orbit in perfect circles, but rather in an ______.
  4. 6. Earth's sister planet, similar in size and orbit but super heated by greenhouse gases.
  5. 7. The _____ theory suggested the earth was at the center of the universe.
  6. 10. Largest planet in our solar system that is thought to prevent the formation of a 9th planet in the asteroid belt region
  7. 12. A theory that explains the birth of the Universe through an enormous explosion.
Down
  1. 1. Phenomena observed when wave frequency is altered by the movement of its source, like a siren on a police car driving by.
  2. 4. Change in color frequency that would be observed for an incoming asteroid
  3. 8. A stage the life of a star where an alternate fuel source causes a dramatic increase in size.
  4. 9. A cluster (group) of stars, dust, gas, and other particles in a region of the universe
  5. 11. A celestial body with unique orbit around a central star.