1. Ancient Greek Astronomy

2. The First Greek Astronomers
The time when Greek astronomy was at its peak was between 700 BC-300 AD
The Ancient Greeks, at first, were very superstitious and believed that the world was very supernatural but later turn their theories around toward the natural.
The Greeks were not primitives and only a few of them believed that earth was the center of the universe.

3. Thales the Astronomer
Thales is considered the first Astronomer and philosopher.
Thales is famous for discovering why eclipses happened and that could predict them.

4. Anaximander Anaximander was after Thales.
He made many advancements in the idea of the sun was larger than the earth.
He believed that the Sun was 27 times larger than the earth.

5. Pythagoras
Pythagoras thought that the universe could be explained with mathematics.
He was most likely the first person to propose the idea of a round earth.

6. Some time in his life Pythagoras started a school of thought.
His followers were called the Pythagoreans.
The Pythagoreans highly developed the cause of astronomy.
They proposed that the earth wasn’t the center of the universe. The Pythagoreans were the first to develop this.

7. Plato Plato was the student of Socrates.
He thought that astronomy was only good for studying nice things and for further developing mathematics.
Be cause of Plato the development of astronomy halted for some time.

8. Eudoxus of Cnidus Eudoxus just built on his predecessor's theories.
He then formed theories with mathematics and with out any observation so his theories could have been proven wrong with simple observations.

9. Autolycus Autolycus started in astronomy in or around 330 BC.
Autolycus believed Eudoxus’ theories.
After Autolycus the center of astronomy shifted from Athens to Alexandria.

10. Aristarchus of Samos
Aristarchus tried to find the distances of the heavenly bodies.
When he tried to find the distances of the sun and the moon he didn’t get any conclusive data but it did show that the sun was much farther than the moon.
Aristarchus also tried to find the sizes of the heavenly bodies.
Aristarchus found that the sun was very large so he formed a model of the universe with the sun in the middle.
Even though he was right the people around him laughed at him for his theory.

11. Eratosthenes
Eratosthenes calculated the size of the earth and improved on Aristarchus’ theories.
In 240 BC Eratosthenes thought that the earth was 25,000 miles around. He was only 1,000 miles off.

12. Hipparchus He was famous for using science to form his theories.
He used trigonometry to find the distances of the heavenly bodies.

13. Hipparchus used the Earth shadow during a lunar eclipse to find out how far away the moon was.
Hipparchus found out how long it took for the moon to revolve around the earth.
He, in 129 BC, charted over 1080 stars.
Hipparchus also discovered that it would take 26,000 years for the earth’s axis to rotate 360 degrees.

14. Ptolemy Most of Ptolemy’s work was based off of Hipparchus’ work.
He disregarded the astronomers before him and believed that the earth was round but that it didn’t spin.

15. After Ptolemy there were no more great Greek astronomers
After Ptolemy there were no more great Greek astronomers. So Greek Astronomy ended after Ptolemy.
Even though their time ended they paved the way for astronomers after them.

16. The End