1. Martian Canali

2. Viking Lander

3. Labeled release experiment (LR) Moistened soil sample with a liquid nutrient medium that contained carbon-14. Container monitored to see if carbon-14 released into air.

4. Control samples Martian soil samples were heated to 160 C, a temperature that destroyed all biological activity in terrestrial soils before testing, and then tested with the same three experiments.

5. Life on Mars?

6. Molecular analysis Experiment Heated soil to look for organic molecules. Found a complete absence of any organic molecules in the Martian soil.

7. The Conclusion The Martian surface is completely devoid of life. Gas release was due entirely to chemistry. High concentrations of chemicals such as hydrogen peroxide and strong ultraviolet radiation combine to make the surface of Mars completely sterile.

8. Inconclusive? These three experiments have been shown since the seventies to miss life present in arid regions on Earth. Assumed, incorrectly, that all life got energy either from photosynthesis or by eating organic compounds.

10. Fossilized bacteria?

11. Beagle 2 Landed on Mars Christmas day 2003 Contained a mass spectrometer 100 times more sensitive than Vikings’ to look for organic molecules and peroxides in soil Test for carbon-12 to carbon-13 ratio

12. Mars Rover

16. Grey Hematite

19. Opportunity landing site

25. Curiosity

26. Gale crater Curiosity landing site

27. Gale Crater

29. The Face on Mars

38. Exam 2 Tuesday Covers Chapters 7-10, & 14 One sheet of notes with writing on one side only

39. Jovian Planets

40. Discussion Why do you think it is that of the Jovian planets we know the most about Jupiter?

41. Discussion Jupiter is 71% hydrogen, 24% helium, and 5% heavier elements. How can we figure out the composition of Jupiter?

42. Discussion Jupiter has more heavy elements than the Sun does. If both formed from the same nebula, why do you think that is? Jupiter: 71% hydrogen, 24% helium, 5% heavier elements Sun: 73.4% hydrogen, 25% helium, 1.6% heaver elements

43. Discussion Jupiter is 3 times as massive as Saturn, yet is only 1.2 times bigger. Why do you think that is?

44. Mass-radius relation

46. Discussion All the Jovian planets are covered with thick clouds. How do you know anything at all about the interior of the Jovian planets if we cannot obverse them?

47. Clues to internal structure 1.Mean density 2.Gravitational mapping 3.Shape of the planet

48. Mean density of planets Earth 5.5 g/cm 3 Mercury 5.4 g/cm 3 Venus 5.2 g/cm 3 Mars 3.9 g/cm 3 Moon 3.4 g/cm 3 Neptune 1.6 g/cm 3 Sun 1.4 g/cm 3 Jupiter 1.3 g/cm 3 Uranus 1.3 g/cm 3 Saturn 0.7 g/cm 3

49. Rotation The Jovian planets tend to spin very fast Jupiter – 9 h 55 m 29 s Saturn – 10 h 39 m 25 s Uranus – 17 h 14 m 24 s Neptune – 16 h 6 m 36 s

50. Discussion What happens as the rotation rate of a planet is increased?

51. Oblateness

52. Jupiter’s oblateness Equatorial radius: 71,492 km Polar radius: 66,854 km or 6.5% smaller. Oblateness 6.5

53. Discussion How does the oblateness of a planet depend on the rotation rate, the size, and the mass of a planet?

55. Discussion Saturn’s diameter at its equator is 10% larger than its pole to pole diameter. Saturn is smaller than Jupiter and rotates more slowly. How come its equatorial bulge is bigger?

56. Saturn’s internal structure For Saturn’s size and density, it is not oblate enough to have the same internal structure as Jupiter. Saturn has a larger rocky core, comprising about 10% of its total mass (about 9.5 Earth masses).

58. Discussion Why is Saturn’s liquid metallic hydrogen layer so much smaller than Jupiter’s?

59. Discussion The equators rotate faster than the poles. The poles on Jupiter take and extra 5 minutes to complete a rotation. With differential rotation and a big liquid metallic interior, what do you expect to be the result?

60. Jupiter’s magnetic field

63. Discussion If Jupiter and Saturn rotate differentially, how do we decide what their rotation rates are?

64. Discussion Saturn’s magnetosphere is not as big as Jupiter’s, between 10 to 20 % that of Jupiter. Why not?

65. Discussion Unlike the terrestrial planets that receive most of their energy from the Sun, the planet Jupiter emits about twice as much energy as it receives from the Sun. Where do you think this energy comes from?

66. Jupiter as a failed star Core at a pressure of 70 million atm Temperature 22,000 K Jupiter would need 80 times its current mass to start hydrogen fusion in its core.

67. Jupiter’s atmosphere Hydrogen 86.4% Helium13.6% Water0.1% Methane0.21% Ammonia 0.07%

69. Discussion Jupiter, like the Earth has a stratosphere. Why do you think that is?

71. Cloud bands Why do you think Jupiter has cloud bands?

73. Discussion The boundaries between the zones and belts on Jupiter mark a change in wind direction with typical speeds of 500 km/hr. What causes these strong eastward and westward winds on Jupiter?

74. Jupiter in the IR and visible

75. Discussion What does the infrared picture of the bands tell you about the difference between the belts and zones of Jupiter?