1. Giant Planets Neptune Uranus Saturn Jupiter
Point out the clouds, whose colors come from organic chemicals we don’t fully know. Note that “organic” means compounds with H,C,N,O, not “live”. Shadow of Io. Red Spot. Bands. Other smaller storms (white ovals).
Jupiter

2. Notes: Read Chapter 11: “Jovian Planet Systems”
Homework: in Mastering Astronomy due Friday.

3. Results from Midterm 1

4. Terrestrial (Rocky) Outer 4 Planets: Gaseous Giants
The Solar System
Note the different scale of the inner and outer solar system. Note that Mercury and Pluto have the largest orbital inclinations. Note the tilts of the different planets (Venus upside down, Uranus sideways). We used to think these were due to giant impacts (and maybe they are), but recent work has also shown that frictions between core, mantle, and atmosphere can lead to large tilt changes. The Moon may act to stabilize the Earths tilt.
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5. Spacecraft Reconnaisance
1980’s: Voyager 1 & 2
Camera
Spectrometer
Measures spectral lines:
Chemical composition
Visited all 4
giant planets

6. Voyager Spacecraft Movie of Jupiter

7. Approach of Voyager Spacecraft In Rotating Frame of Reference
This is the original Voyager 'Blue Movie' (so named because it was built from blue filter images). It records Voyager 1's approach during a period of 60 Jupiter days. Notice the difference in speed and direction of the various zones of the atmosphere.

8. Voyager Spacecraft Movie of Jupiter: In Rotating Frame of Reference

9. Galileo Spacecraft Visited Jupiter
Launched from Space Shuttle 1989

10. Galileo Spacecraft 2003: Dropped into Jupiter’s Atmosphere:
Arrived: 1995
2003:
Dropped into Jupiter’s
Atmosphere:
Measure Chemical
Composition:

11. The 4 “Giant Planets” “Jovian Planets”
No solid surfaces !!!
Much higher mass & radius than Earth, Venus, Mars.
Jupiter Saturn Uranus Neptune
H & He
(most common atoms in universe)
H & He
H2O,
H & He
H2O,
H & He
(text: “hydrogen compounds” = water, methane, ammonia)
“Ice Giants”
This is mostly to discuss relative sizes. Jupiter and Saturn are true gas giants; Uranus and Neptune are more like “ice giants” (though with deep gaseous exteriors). Can mention that it takes a core about the size of their cores to attract gas directly from the solar nebula (which needs to be defined).
All have rocky cores (silicates+iron) of Earth masses

12. Comparison of Sun’s and Jupiter’s composition (as measured by the Galileo Probe)
Remember: No solid surface and consists mostly of H & He.
Distinct interior layers, defined by increasing density inward.
Jupiter Sun Jupiter Sun H
0.742
0.736 Ne
(3)
0.0018 He
0.231(4)
0.249 P
< C
0.009(2)
0.0029 S
(6) N
< 0.012 Ar
< O
<
0.0057
“Z”
0.027
0.015
Fractional composition in mass %.

13. Jupiter – King of the Planets
Mass = solar (318 Earth masses),
Radius = 10.5 … 11.2 Earth radii,
Density = 1.3 g/cc (1.3 x water)
Distance: 5.2AU
Orbital Period: 11.8 years
Rotation period: 9:55 hours.
Flattened Spheroid
11.2 RE
10.5 RE
Point out the clouds, whose colors come from organic chemicals we don’t fully know. Note that “organic” means compounds with H,C,N,O, not “live”. Shadow of Io. Red Spot. Bands. Other smaller storms (white ovals).
© 2005 Pearson Education Inc., publishing as Addison-Wesley

14. Saturn © 2005 Pearson Education Inc., publishing as Addison-Wesley
Mass = 95 Earths (only 30% of Jupiter)
Radius = 9.4 Earths
Density = 0.7 gram/cm3 (floats)
Distance: 9.5 AU
Orbital Period: 29.4 years
Rotation period: 10.6 hours.
Rings: Composed of billions of icy rocks and icy dust particles (water ice and silicates).
We’ve already discussed most of the interesting planetary aspects of Saturn, since it is much like Jupiter. We’ll come back to the rings later.
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16. Interior of Jupiter and Saturn

17. “Phases” of Hydrogen: The Interiors of Jupiter & Saturn
Temperature (K)
Density

18. Molecular and Metallic hydrogen
Computer Simulation:
Molecular and Metallic hydrogen
Molecular hydrogen
Metallic hydrogen
Electrons bound to molecules
Electrons free to move

19. “Phases” of Hydrogen: The Interiors of Jupiter & Saturn
Temperature (K)
Density

20. A New Probe of Jupiter: “Juno” Launch August 5, 2011

21. Interior of Jupiter A New Probe: “Juno”

22. Surfaces of the Giant Planets

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24. Jupiter

25. Jupiter’s Atmospheric Properties
Rotation Period = 9 hours 55 minutes
(based on Jupiter’s magnetic field)
Cassini (2000)
Rotation Period = 9 hours 55 minutes (based on Jupiter’s magnetic field) Cassini (2000)

26. Jupiter’s Atmosphere
Cassini (2000)

27. Jupiter’s Atmosphere
Cassini (2000)

29. Bands of Jupiter What Causes them?
Convection on Jupiter:
Bands of Jupiter What Causes them?
Warm air rises
Coriolis force
diverts path sideways
Coriolis force is due to
rotation of planet
Jupiter rotates fast:
Period = 10 hours

30. Winds of Jupiter’s Bands
Red Spot
in Southern
Hemisphere

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32. Great Red Spot
A Hurricane that has
lasted 300 years
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33. Giant red spot in motion

34. Red Oval in motion
Red Oval in motion

35. Cyclones and Anticyclones on Jupiter

36. Computer Simulation of Cyclone Formation

37. Red Spot Jr. spot formed from three white ovals and later turned red.

38. Cyclonic Motions Coriolis effect: Motion from High Pressure area
Southern
Hemisphere
Counterclockwise: high P
Northern
Hemisphere

39. Comparison of Cyclones and Anti-Cyclones
Low pressure weather phenomena,
Winds blow inwards,
Typical storm systems on Earth
Rotate counter-clockwise on Northern hemisphere,
Rotate on clockwise on Southern hemisphere,
Anti-Cyclones:
High-pressure weather phenomena,
Winds blow outwards,
Example: Jupiter’s red spot
Rotate clockwise on Northern hemisphere,
Rotate counter-clockwise on Southern hemisphere,
Anti-cyclone on northern HS
Cyclone on the northern HS
Anti-cyclone on the southern HS
Cyclone on the southern HS
What is this?
Counterclockwise: high P

40. Comparison of Cyclones and Anti-Cyclones
Low pressure weather phenomena,
Winds blow inwards,
Typical storm systems on Earth
Rotate counter-clockwise on Northern hemisphere,
Rotate on clockwise on Southern hemisphere,
Anti-Cyclones:
High-pressure weather phenomena,
Winds blow outwards,
Example: Jupiter’s red spot
Rotate clockwise on Northern hemisphere,
Rotate counter-clockwise on Southern hemisphere,
What is this?
Anti-cyclone on northern HS
Cyclone on the northern HS
Anti-cyclone on the southern HS
Cyclone on the southern HS
Counterclockwise: high P

41. Jovian Storms Planet Rotation Red Spot: A High Pressure Storm Jupiter
Analogous to hurricanes (low pressure systems, material flows in), but they rotate in the opposite direction because they high pressure systems where material flow out
Jupiter
the Great Red Spot
we are not sure why it is red
Neptune
the Great Dark Spot
Planet
Rotation

42. Uranus – Haze but any Clouds?
Mass = 14.5 Earths Orbital Period: 84 years;
Radius = 4.0 Earths
Density = 1.3 gram/cm3 = 1.3 x water
Distance: 19.2 AU Rotation period: 17.2 hours.
Visible Light
Infrared Light (Thermal Emission)
Featureless in visible light, because clouds are below haze layer of methane (colder than Saturn).
Featureless in visible light, because clouds are below haze layer of methane (colder than Saturn).

43. Uranus – Yes Plenty of Clouds
Visible Light
Featureless in visible light, because clouds
are below haze layer of methane (colder than Saturn).

44. Uranus – Yes Plenty of Clouds

45. Neptune Mass = 17 Earths Radius = 3.9 Earths Density = 1.76 x water
Distance: 30 AU
Orbital Period: 163 years;
Rotation period: 16.1 hours.
Neptune
Cyclonic storms.

46. Uranus & Neptune Giants of H, He, and Water!
Gaseous envelope of H, He, and some CH4
Liquid mixture of H2O, CH4, NH3 ices
Rocky core (silicates+iron)

47. Hydrostatic Equilibrium: Pressure balance
Pressure at any depth = gravitational weight of column above
“Hydrostatic equilibrium” governs the structure of all planets.
The inside has higher pressure and density because of the weight of the overlying material.
Temperature at center is ~20000K. Note relation between temperature and pressure – pressure needed to prevent collapse (and more upper weight requires more pressure). Note odd state of metallic hydrogen (conducting – semi-free electrons). Core is uncertain (current limit about 5 earth masses – that’s odd).
© 2005 Pearson Education Inc., publishing as Addison-Wesley

48. Inside Giant Planets
Saturn emits almost twice as much energy as it absorbs from the Sun.
Neither Cooling nor Radioactivity can account for it
Saturn must a different “secret” heat source
Jupiter has 3x more mass than Saturn, but is only slightly larger in radius!
the added weight of H & He compresses the gases below to a higher density
like stacking pillows
If Jupiter had 10x its mass, it would have same radius ! Add even more mass, and Jupiter would get smaller !
Jupiter is as large as a planet can get.
Uranus & Neptune have less mass than Saturn, yet
they have higher densities
They must be made of denser material:
More Rock & Water !

49. How do you construct a model for Jupiter’s interior?
A typical Jupiter model is based on
Hydrogen-helium relationship between pressure-density-temperature
Abundance of all atoms from measurements (Galileo probe)
Gravitational “shape”, inferred from fly-by trajectories (Galileo & Cassini missions)

50. Large core, little ice in envelope
Two different models for Jupiter’s interior
Militzer et al. model
Large core, little ice in envelope
For Models to agree with the Radius, Mass, and Shape of Jupiter:
Core is 10 Earth masses.
But there are two different
Models: H20 sunk or spread.
Saumon-Chabrier model:
Small core, lots of ice in envelope

51. Determining the Density inside a Rotating Planet
Use Motion of Orbiting Satellites
Rotation flattens shape
—> Less pull on satellite at poles
Higher density
toward center
—> Exerts Point-like Gravitational Force
Track acceleration of
satellites accurately
—> Density profile throughout interior

52. Interactive Quiz How would you land on Jupiter? With parachutes
With thrust rockets
With pontoons like a seaplane
You cannot land on Jupiter.

53. Interactive Quiz How would you land on Jupiter? With parachutes
With thrust rockets
With pontoons like a seaplane
You cannot land on Jupiter.

54. Moons orbiting the Giant Planets
Thursday’s Lecture:
Moons orbiting the Giant Planets
A volcanic explosion can be seen silhouetted against dark space over Io's brilliant limb. Io more volcanically active than Earth.
How many Jovian moons are there?
Jupiter’s Moon: Io

55. Jupiter – King of the Planets
Radius = 10.5 … 11.2 Earth radii
Make a bigger Earth that has a radius 10 times larger. Assume the density would be the same, what would its mass be?
The same, one Earth mass
10 Earth masses
100 Earth masses
1000 Earth masses
Point out the clouds, whose colors come from organic chemicals we don’t fully know. Note that “organic” means compounds with H,C,N,O, not “live”. Shadow of Io. Red Spot. Bands. Other smaller storms (white ovals).
© 2005 Pearson Education Inc., publishing as Addison-Wesley

56. Jupiter – King of the Planets
Radius = 10.5 … 11.2 Earth radii
Make a bigger Earth that has a radius 10 times larger. Assume the density would be the same, what would its mass be?
The same, one Earth mass
10 Earth masses
100 Earth masses
1000 Earth masses
Point out the clouds, whose colors come from organic chemicals we don’t fully know. Note that “organic” means compounds with H,C,N,O, not “live”. Shadow of Io. Red Spot. Bands. Other smaller storms (white ovals).
But Jupiter’s mass is only 318 Earth masses. What does this tell us?
© 2005 Pearson Education Inc., publishing as Addison-Wesley

57. Size of Rocky Planets
Make the Earth a 1000 times more massive. How large would its radius be?
The same, one Earth radius
3 Earth radii
6 Earth radii
10 Earth radii
Point out the clouds, whose colors come from organic chemicals we don’t fully know. Note that “organic” means compounds with H,C,N,O, not “live”. Shadow of Io. Red Spot. Bands. Other smaller storms (white ovals).
© 2005 Pearson Education Inc., publishing as Addison-Wesley

58. Size of Rocky Planets
Make the Earth a 1000 times more massive. How large would its radius be?
The same, one Earth radius
3 Earth radii (because of gravity!!)
6 Earth radii
10 Earth radii
Point out the clouds, whose colors come from organic chemicals we don’t fully know. Note that “organic” means compounds with H,C,N,O, not “live”. Shadow of Io. Red Spot. Bands. Other smaller storms (white ovals).
© 2005 Pearson Education Inc., publishing as Addison-Wesley

59. Saturn’s
Storms
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60. After 15 years of winter on Saturn’s Northern hemisphere, spring arrives with gigantic storms
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Neptune’s
Storms
scooter
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62. Jupiter’s Cloud Layers
Convection in the troposphere causes Jovian weather.
Warm gas rises to cooler altitudes, where it condenses to form clouds.
Three gases condense in the Jovian atmosphere:
ammonia (NH3) (high altitude)
ammonium hydrosulfide (NH4SH)
water (H2O)
They condense at different temperatures, so their clouds form at different altitudes.
Altitude above clouds tops (km)
Temperature (°C)

63. The Jovian Atmospheres
The temperature profile of each planet determines the color of its appearance.
Cloud layers form where a particular gas condenses.
Saturn has the same cloud layers as Jupiter.
they form deeper since Saturn is colder overall
they are spread farther apart since Saturn has lower gravity
Uranus & Neptune
cold enough to form methane clouds

64. Aurora Borealis near Jupiter’s North Pole

65. Auroral Zones
The high energy particles come down the magnetic field lines and hit the atmosphere near the poles, causing the gases to glow. Just like on the Earth, this makes an “aurora” in a ring-like zone.
These auroral pictures are taken in UV light.
© 2005 Pearson Education Inc., publishing as Addison-Wesley

66. Magnetic Fields
Saturn
Jupiter
Uranus
Neptune

67. Jupiter's Magnetosphere
Ion and neutral mass spectrometer instrument on the Cassini spacecraft, makes the huge magnetosphere surrounding Jupiter visible. The magnetosphere is a bubble of charged particles trapped within the magnetic environment of the planet. In this picture, a magnetic field is sketched over the image to place the energetic neutral atom emissions in perspective.
Also shown for scale and location are the disk of Jupiter (black circle) and the approximate position (yellow circles) of the doughnut-shaped torus created from material spewed out by volcanoes on Io, one of Jupiter's large moons.

68. Jupiter’s Magnetosphere – Bigger than the Sun
Solar Wind
protons &
electrons
The metallic hydroden is conducting. Jupiter’s field is quite strong.
© 2005 Pearson Education Inc., publishing as Addison-Wesley

69. Jovian Magnetospheres
Saturn, Uranus, & Neptune have smaller & weaker magnetospheres.
fraction of electrically conducting material in interiors is smaller
Solar wind is weaker farther out, or else their magnetospheres would be even smaller
we can not explain the magnetic field tilts of Uranus & Neptune.

70. Inside the Jovian Planets
All Jovian cores appear to be similar.
made of rock, metal, and Hydrogen compounds
10 x the mass of Earth
Uranus & Neptune captured less gas from the Solar nebula.
accretion of planetesimals took longer
not much time for gas capture before nebula was cleared out by Solar wind
Only Jupiter and Saturn have high enough pressure for H & He to exist in liquid and metallic states.
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71. Quiz
If Jupiter formed in a protoplanetary disk that had twice as much dust in it:
Would have a bigger core
Might have more hydrogen
Might have more metallic hydrogen
All of the above

72. Quiz
If Jupiter formed in a protoplanetary disk that had twice as much dust it:
Would have a bigger core
Might have more hydrogen
Might have more metallic hydrogen
All of the above

73. Why are the Jovian Planets Massive and Gaseous (H, He) ?
Formed beyond the frost line (3 AU):
so cold that ice particles exist with silicate dust.
Ice and Dust collides, sticks grows into icy-rocky core.
Core’s gravity captures H/He gas
Planet attracts ices and dust that orbit
Moons formed out of these disks: A miniature solar system.
Young Solar System:
Gas & Dust
Young Jupiter
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