1. Chapter 1 The Copernican Revolution

2. The planets’ motions Wanderers among the stars Retrograde motion

3. Figure 1.1 Planetary Motions

4. Geocentric models of the Universe Earth at center of solar system Aristotle (384 - 322 B.C.) Ptolemy (87 - 150 A.D. approximately)

5. Figure 1.2 - Geocentric Model

6. Figure 1.3 - Ptolemy’s Model

7. History of modern astronomy and heliocentric models Sun at center of solar system Copernicus (1473 - 1543) Brahe (1546 - 1601) Galileo (1564 - 1642) Kepler (1571 - 1630)

8. Figure 1.4 - Nicholas Copernicus 1473 - 1543

9. Figure 1.5 - Retrograde Motion

10. Figure 1.6 - Galileo Galilei 1564 - 1642

11. Figure 1.7 Galilean Moons

12. Figure 1.8a - Venus Phases Sun-centered model

13. Figure 1.8b - Venus Phases Ptolemy’s model

14. Figure 1.9 - Johannes Kepler 1571 - 1630

15. Figure 1.10 Tycho Brahe 1546 - 1601

16. Kepler’s laws of planetary motion 1st law - elliptical orbits 2nd law - equal areas in equal times 3rd law - P 2 proportional to a 3

17. Figure 1.11 - Ellipse

18. Figure 1.12 Orbital Properties

19. Figure 1.13 - Kepler’s Second Law

20. Figure 1.14 - Astronomical Unit

21. Figure 1.15 - Isaac Newton 1642 - 1727

22. Newton’s Three Laws of Motion 1. Motion remains constant unless force acts 2. Force = mass X acceleration 3. Forces occur in pairs on two bodies

23. Figure 1.16 Newton’s First Law

24. Newton’s Law of Gravity The force of gravity is Stronger with larger masses Stronger with smaller distances

25. Figure 1.17 - Gravity

26. Figure 1.18 Gravitational Force

27. Figure 1.19 Sun’s Gravity

28. Figure 1.20 - Center of Mass

29. Figure 1.21 Orbits