1. Chapter 4 Test Study Guide
Origins of Astronomy

2. 1. Why did Copernicus hesitate to consider alternatives to the Ptolemaic Universe?
It contradicted Christian Theology at the time

3. Earth’s position in the universe
2. What was the most controversial issue about eh nature of the universe?
Earth’s position in the universe

4. 3. What was the name of Copernicus’ book?
De Revolutionimbus

5. 4. His geocentric model dominated astronomy for 2,000 years.
Aristotle

6. 5. Define First Principle
Something that is held obviously true and needs no further examination.

7. 6. Most Greek philosophers accept this as a first principle.
Earth was the unmoving center of the universe.

8. 7. Why did early astronomers believe the earth did not move?
Because they saw no parallax.

9. 8. What are the small circles called that Ptolemy used to describe the motions of planets?
Epicycles

10. 9. Philolaus believed this about the universe.
Earth moved around a central fire

11. 10. Galileo was a strong supporter of this astronomer
Copernicus

12. 11. The occasional westward motion to the planets is called
Retrograde motion

13. 12. Whose death ended the 99 years that revolutionized astronomy?
Galileo

14. 13. What are Kepler’s three laws of planetary motion?
1. The orbits of the planets are ellipses with the Sun at one focus.
2. A line form a planet to the Sun sweeps over equal areas in equal intervals of time.
A planet’s orbital period squared is proportional to its average distance form the Sun.

15. 14. Which planet goes through a complete set of phases like our moon?
Venus

16. 15. The transit of Venus disproves this astronomers model
Ptolemy

17. 16. He found no parallax with the discovery of a new star disproving the Ptolemaic Theory.
Tycho

18. 17. Tool Galileo is known for using
Telescope

19. 18. First person to point the telescope at the sky
Galileo

20. 19. Believed heavens were perfect with perfect spheres rotating at a constant rate carrying objects in circles.
Plato

21. 20. Who discovered four of Jupiter’s moons?
Galileo

22. 21. He calculated Earth’s radius by verifying the position of the Sun in two cities and the distance between those two cities.
Eratosthenes

23. 22. Determined that the orbits of planets around the Sun are ellipses.
Kepler

24. 23. Who said the Milky Way was made up of stars too faint to see with the naked eye?
Galileo

25. 24. List the four Galilean moonsIo
Callisto
Ganymede
Europa

26. 25. Who was excommunicated from the church and placed on house arrest?
Galileo

27. 26. Define archeoastronomy
Science field focused on connections of ancient celestial observations and structures

28. 27. Explain the Geocentric Universe Model
Model of the universe with the Earth at the center

29. 28. Explain the Heliocentric Universe Model
The model of the universe with the Sun at the center.

30. 29. He was Tycho’s assistant
Kepler

31. 30. She arranged the star classification system to reflect temperature
Annie Jump Cannon

32. 31. He had a pet moose
Tycho

33. 32. First astronomer to study Cepheid Variable Stars
Henrietta Leavitt

34. 33. Wrote books in Italian instead of Latin
Galileo

35. 34. Classified stars according to spectral type, A through Q
Williamina Fleming

36. 35. Huge change in peoples thinking from geocentric to heliocentric
Copernican Revolution

37. 36. Law that helped establish that the universe is expanding
Hubble’s Law

38. 37. His books were banned and he was put on house arrest
Galileo

39. 38. First to explain why Earth has seasons
Copernicus

40. 39. Label the Diagram