p. 96

1. Mars Terrestrial planets Mercury Venus Earth Mars Background Sun Sun Moon Earth Venus Mercury p. 96

2. Composed of clusters of galaxies. Each cluster has 25 to 1,000 galaxies. Each galaxy has 108 to 1012 stars. Besides stars there are: Nebula Planets Black Holes Dark matter The Universe

5. Earth and Venus – sister planets, Venus 95% in size of Earth Fig. 6-1, p.97

7. Earth and Moon 1992 Galileo spacecraft Fig. 6-2, p.98

8. AST0601.jpg

9. AST0616.jpg

10. Interior of terrestrial planets Fig. 6-3, p.98

11. Fig. 6-8, p.102

12. TIDES

13. Solar tides are about 50% of lunar tides. If Sun, Earth and Moon are on one line, then the two tides add. This is during New and Full Moon. 1 + 0.5 = 1.5 times Moon alone. If Sun and Moon are at right angles, then tides subtract. This is during first quarter and last quarter. 1 – 0.5 = 0.5 times Moon alone. Ratio of the high tides 1.5/0.5 = 3!!! Lunar and Solar Tides

14. Earth’s Magnetic Field Magnetic and geographic north poles are about 1,000 mile apart.

15. Fig. 6-12, p.105

16. Aurora Particles from the Sun entering Earth atmosphere Fig. 6-13b, p.106

17. Third quarter Moon Fig. 6-14, p.106

18. Moon rock Fig. 6-15, p.107

19. Natural radioactive elements, such as uranium decay over time. Half life is time that half the nucleus of atoms decay. Uranium U(238) (isotope) half life is 4.6 billion years to Lead Pb(206). In 4.6 billion years half would be left. In 9.2 billion years one quarter will be left. Measuring the ratio of Pb(206) to U(238) in a rock, the age is computed when rock was formed. Radioactive Dating

20. Age of Moon rocks. Oldest rock on Earth is 3.9 billion years. Most meteors have age of 4.5 billion years, age of solar system. Fig. 6-16, p.109

21. AST0609.swf

22. Crater Formation Crater formation

23. Arizona Meteor Crater Diameter about 1,200 meters (4,000 ft).

24. Far side of the Moon Fig. 6-18a, p.110

25. Moon Fig. 6-18b, p.110

26. Apollo 17, 1972 Fig. 6-21, p.110

27. Apollo 11, 1969 Fig. 6-23, p.111

28. Mercury and Venus can never be seen at midnight, Fig. 6-26, p.113

29. Albedo: fraction of light reflected Fig. 6-29, p.115

30. Mercury Moon Mars Venus Fig. 6-31, p.116

31. Mercury Fig. 6-33, p.117

32. Mercury Fig. 6-34, p.118

33. Mercury Best picture from Earth Fig. 6-35, p.118

34. Venus Best picture from Earth Fig. 6-37, p.119

35. Venus Atmosphere Fig. 6-39, p.119

36. Greenhouse effect. Fig. 6-40, p.120

37. Venus Mount Mons Fig. 6-43, p.123

38. Atmosphere of a planet depends on two factors: Escape velocity and max surface temperature vesc = √(2GM/R) v ~ √(T/m) [m-molecule mass] Relative masses of molecules H2=2, He=4, O2=32, CO2=44 Earth – 11.2 km/s (25,000 mi/hr, 40,000km/hr) 330ºK Mercury – 4 km/s 700ºK Venus – 10.4 km/s 750ºK Mars – 5 km/s 290ºK Jupiter - 60 km/s 165ºK Saturn – 35 km/s 135ºK Uranus – 21 km/s 75ºK Neptune – 23 km/s 70ºK Pluto - 1.1km/s 50ºK Moon – 2.4 km/s ~300ºK Atmosphere

39. Mars Hubble Space Telescope

40. Questions on Mars! • Was there running water (rivers) on Mars. • Where is the water now? • Was (is) there any primitive life on Mars? • Why is Mars the best planet to colonize?

41. Mars dust storms

42. Mars Pathfinder Fig. 6-47, p.126

43. Mars Olympus Mons Fig. 6-48a, p.127

44. Fig. 6-50b, p.128

45. Mars Dry river beds Fig. 6-50a, p.128

46. Fig. 6-52, p.129

47. Viking Fig. 6-54, p.130

50. AST0618.jpg