1. Ancient Greek and European
Astronomers
Directions: Read carefully through ALL of the slides presented (total of 18; on a 15 second timer per slide); TAKE BRIEF NOTES on each of the 13 Astronomers presented; When finished, show your notes to the SUB to get a copy of the quiz, STAPLE your PPT notes behind the quiz, and then answer the 13 Matching items on the Quiz provided (YES, open notes!) Then turn your completed quiz in to your class period tray to be graded.

2. Thales
B.C.
Considered to be the
first true “Greek
philosopher”
Predicted a solar eclipse
on May 28, 585 B.C.
Known for attempting to
find natural
explanations for events,
rather than supernatural
ones

3. Philolaus
B.C.
The first person to ever
think that the Earth was
not at the center of the
universe.
Believed that the Earth
and everything else
revolved around an object
in space called the
“Central Fire”

4. Hipparchus
B.C.
Considered to be the greatest ancient astronomer
Developed a very accurate method of predicting eclipses
Developed the first catalog of stars, ranking them by brightness, which he called “magnitude”

5. Pythagoras
B.C.
Mathematician known as “father of numbers”
Best known for the Pythagorean Theorem
One of the first people to think that Earth was round
Said all planets revolved around a central point
Thought of the Moon as a planet called “Counter-Earth”

6. Aristarchus
B.C.
First person to present a heliocentric model of the Solar System, with the Sun at the center
This idea was mostly rejected for the next 2,000 years.

7. Eratosthenes
B.C.
Calculated the circumference of the Earth and the tilt of Earth’s axis with amazing accuracy
May have also calculated the distance from Earth to the Sun

8. Aristotle
B.C.
The teacher of Alexander the Great
The most influential of Greek philosophers
He believed that the Earth was in the center of the universe, and that the Moon, then the Sun, then the other planets and stars revolved around Earth.

9. Geocentrism

10. Ptolemy
A.D.
Roman citizen
Changed Aristotle’s geocentric model to include “epicycles” upon which the planets moved
This was an attempt to account for the observed “retrograde motion” of planets in the sky

11. Geocentrism
with epicycles

12. St. Thomas Aquinas
A.D.
Italian Catholic priest, considered by many to be the Church’s greatest philosopher
Declared in the 1200s A.D. that Ptolemy’s geocentric model with epicycles was a biblical model.
Geocentrism became part of Canon Law.

13. Nicolaus Copernicus
A.D.
Polish man who was very religious
Astronomy was not his main work, but it is what he is best known for
Developed the first comprehensive heliocentric model of the solar system
He did this in spite of Canon Law and Ptolemy.

14. Tycho Brahe
A.D.
From Denmark
Measured the positions of the planets very accurately for 30 years
A popular man with a short temper
Brahe never published his work

15. Johannes Kepler
A.D.
German
Tycho Brahe’s young assistant
When Brahe died, Kepler inherited all of Brahe’s measurements
Kepler used the work to provide evidence that firmly supported the heliocentric model of Copernicus

16. Galileo Galilei
Italian
Called the “father of modern astronomy” and “father of modern science”
Made significant improvements to telescopes
Used telescopes to build scientific support for heliocentrism

17. Galileo Galilei
Galileo’s evidence included:
Moons orbit Jupiter—and so not everything orbits Earth
There are mountains and craters on the Moon—and so not everything in the heavens is “perfect”
Venus goes through “phases” just like the Moon—so it must orbit the Sun

18. Phases of Venus