1. Chapter 7 The Jovian Planets

2. Jupiter from Spacecraft Cassini

3. Figure 7.1 Jupiter a) earth based telescope, b) HST

4. Figure 7.2 Saturn from HST

5. Spacecraft Jovian Exploration Gravity assist Voyager 1 & 2 Galileo Cassini-Huygens

6. More Precisely 7-1 Gravitational “Slingshots”

7. Voyager 1 & 2 spacecraft Launched 1977 Reached Jupiter 1979 Used gravity assist 1 reached Saturn 1980 2 reached Saturn 1981 2 reached Uranus 1986 2 reached Neptune 1989

8. More Precisely 7-1 Gravitational “Slingshots”

9. Galileo spacecraft Launched 1989 Three gravity assists through inner solar system Reached Jupiter December 1995 Probe entered Jupiter’s atmosphere Orbiter studied Jupiter’s moons

10. Figure 7.10 Galileo’s Atmospheric Probe Entry Site

11. Figure 7.3 Jupiter from Cassini (on way to Saturn)

12. Cassini-Huygens spacecraft Launched October 1997 Reached Saturn July 2004 Cassini - orbiter and Huygens - probe Huygens entered Titan’s atmosphere January 2005

13. Figure 7.4 Uranus from Voyager 2

14. Uranus Discovered by William Herschel in 1781 Barely visible to naked eye Orbit not exactly elliptical Another planet influencing it

15. Figure 7.5 Neptune from Voyager 2

16. Discovery of Neptune Orbit predicted by Englishman John Adams 1845 and Frenchman Urbain Leverrier 1846 First seen by German Johann Galle 1846

17. Figure 7.6 Jovian Planets - Relative size

18. Table 7.1 Planetary Properties

19. Rotation rates Not solid - differential rotation Atmosphere at various latitudes rotate different rates Magnetosphere rotates

20. Jovian Planet Physical Properties Strong gravity held original atmosphere - mainly H and He Each has dense compact core Atmospheres liquid in interior

21. Analogy 7.1 Saturn would float

22. Axial tilt (Earth 23.5°) Jupiter 3° Saturn 27° Uranus 98° (axis roughly parallel to ecliptic) Neptune 30°

23. Figure 7.7 Seasons on Uranus

24. Jupiter’s atmosphere Molecular Hydrogen 86% Helium 14% Small amounts of methane, ammonia, H 2 O

25. Figure 7.8 Jupiter’s Convection

26. Cloud bands Lighter zones - warm material rising, high pressure Darker belts - cool material sinking, low pressure

27. Figure 7.9 Jupiter’s Atmosphere

28. Atmospheric layers Haze on top 110 K White ammonia clouds 125 - 150 K Ammonium hydrosulfide ice 200 K H 2 O ice Gaseous H, He, methane, ammonia, H 2 O

29. Weather on Jupiter Great Red Spot White spots Brown oval

30. Figure 7.11 Jupiter’s Red Spot and a white spot

31. Great Red Spot 2X size of earth Large hurricane like storm More than 300 years old Earth hurricanes die out over land

32. Figure 7.12 Jupiter’s Brown Oval

33. Figure 7.13 Saturn a) Voyager 2, b) Cassini

34. Saturn’s atmosphere Molecular H 92.4% Helium 7.4% - less than Jupiter - liquefied and sank Traces of methane and ammonia Less gravity, so thicker than Jupiter’s atmosphere Not as colorful (fewer holes/gaps)

35. Figure 7.14 Saturn’s Atmosphere

36. Figure 7.15 Saturn Storm from HST a) 2 hour intervals b) infrared

37. Figure 7.16 Saturn’s “Dragon Storm”

38. Uranus and Neptune atmospheres Molecular H 84% Helium 14% Methane - Neptune 3%, Uranus 2% Methane absorbs long wavelengths (red) Neptune more blue than Uranus

39. Figure 7.17 Uranus’s Rotation a), b), c) 4 hour interval d) rings and clouds, infrared

40. Figure 7.18 a) Neptune’s Dark Spot (Voyager 2) b) later disappeared

41. Jupiter’s interior Top layers are gas - molecular H At several thousand km, liquid Liquid metallic H Rocky core

42. Figure 7.19 Jupiter’s Interior

43. Saturn’s interior Top layers are gas - molecular H Thinner metallic H layer Larger rocky core

44. Figure 17.20 Jovian Interiors

45. Jovian magnetospheres Stronger than Earth’s Caused by fast rotation Jupiter - largest and strongest magnetosphere Aurora on Jupiter

46. Figure 7.21 Pioneer 10 Mission

47. Figure 7.22 Aurorae on Jupiter

48. Figure 7.23 Jovian Magnetic Fields

49. Jovian internal heating Jupiter - emits 2X more energy than absorbed (left over heat) Saturn - 3X (helium rain and gravitational compression) Neptune - 2.7X

50. Discovery 7-1 A Cometary Impact