2. Read the page Turn the page Go back Research and describe the contributions of scientists to our changing understanding of astronomy, including Ptolemy, Copernicus, Tycho Brahe, Kepler, Galileo, Newton, Einstein, and Hubble, and the contribution of women astronomers, including Maria Mitchell and Henrietta Swan Leavitt Some History about Astronomy

3. Read the page Turn the page Go back Astronomy is the study of matter in outer space.

4. Read the page Turn the page Go back It is the study of planets and stars.

5. Read the page Turn the page Go back It is the study of the sun and the moon.

6. Read the page Turn the page Go back The scientists who study these things are called astronomers.

7. Read the page Turn the page Go back For thousands of years, men have wanted to understand how the universe works.

8. Read the page Turn the page Go back Learn more In 140 AD, Ptolomy, an astronomer from Greece, wrote a book. He said that the sun, moon and planets orbited around the earth. This theory is wrong, but people believed this for many years. earth moon sun Greece

9. Read the page Turn the page Go back Learn more In 1543, Copernicus, an astronomer from Poland, published a book stating that the planets, including Earth, moved around the sun. Few people believed him. Poland

10. Read the page Turn the page Go back Learn more In the 1600’s, Galileo, an astronomer from Italy, used the newly invented telescope to look at the sky. Galileo believed that Copernicus was right, that the planets, including Earth, moved around the sun. Italy

11. Read the page Turn the page Go back Learn more In 1609, Johannes Kepler, an astronomer from Germany, developed some laws based on the movements of planets. One law was that planets move in an ellipse around the sun, not a circle. Germany

12. Read the page Turn the page Go back Learn more In 1687, Isaac Newton, an astronomer from Great Britain, described a force known as gravity. The planets orbit the sun because of the sun’s gravitational pull. Great Britain

13. Read the page Turn the page Go back Learn more In 1847, Maria Mitchell, an astronomer from America, discovered a comet. She was the first American woman to work as a professional astronomer.

14. Read the page Turn the page Go back Learn more In the 1920’s, Edwin Hubble, an astronomer from America, proved that there are galaxies beyond our own. Hubble Space Telescope

15. Read the page The EndGo back Start Over People continue to be curious about outer space today. Astronomers all over the world continue to learn new things about our universe. I wonder what they will discover next!