Crossword #4

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Across
  1. 2. A person who studies planets and stars
  2. 4. A system of government where the people choose their leaders
  3. 6. A continent where kangaroos are native
  4. 9. The term for the Earth's movement around the sun
Down
  1. 1. A shape with 4 equal sides and no right angle
  2. 3. The imaginary line that divides the Earth into the Northern and Southern Hemispheres
  3. 5. A natural phenomenon that shows a spectrum of colors in the sky
  4. 7. A superhero who wields a hammer named Mjölnir
  5. 8. A famous physicist known for his laws of motion