1. 12a. Jupiter Jupiter data Jupiter seen from the Earth
Jupiter rotation & structure
Jupiter clouds
Jupiter atmospheric motions
Jupiter rocky core
Jupiter magnetic field

2. Jupiter Data (Table 12-1)

3. Jupiter Data: Numbers Diameter: 142,800.km 11.19 ⋅ Earth
Mass: 1.9 ⋅ 1027 kg ⋅ Earth
Density: 1.3 ⋅ water 0.24 ⋅ Earth
Orbit: 7.8 ⋅ km AU
Day: 9h.50m 30s 0.41 ⋅ Earth
Year: years ⋅ Earth

4. Jupiter Data: Special Features
Jupiter is the closest Jovian planet to the Sun
Jupiter is the largest Jovian planet
Jupiter is ~2.5 . mass of all other planets combined
Jupiter has no solid surface
Jupiter has a colorful & dynamic atmosphere
Great Red Spot, belts & zones…
Jupiter’s interior consists of three layers…
Atmosphere: Liquid molecular hydrogen
Mantle: Liquid metallic hydrogen
Core: “Metal” & “rock”
Jupiter has 4 large & 63 small known moons
Io is the most volcanically active body known

5. Jupiter As Seen From Earth
The first telescopic observer of Jupiter
Galileo Galilei 1609
Immediately noticed the four largest moons of Jupiter
Recognized the similarity between them and the planets
More recent telescopic observers
Robert Hooke 1664
Noticed the Great Red Spot in the southern hemisphere
It has persisted in some form until now
Cassini 1690
Cloud bands drawn out by Jupiter’s very fast axial rotation
Used these to measure 9h 50m 28s equatorial Jovian day
Discovered Jupiter’s differential axial rotation Rotation
Jupiter rotates fastest at its equator than at its poles

6. Jupiter is Made of Low-Mass Gases
Jupiter is mostly hydrogen & helium
The numbers
By mass ~ 71% H2 ~ 24% He ~ 5% others
By atoms ~ 91% H2 ~ 8% He ~ 1% others
The evidence
Detected spectra of CH4 (methane) & NH3 (ammonia)
Cold H2 & He are extremely difficult to detect
UV spectra detected in 1960
Jupiter does have a rocky & metallic core
May have been the “seed” for the rest of Jupiter

7. Cloud Details in Spacecraft Images
Pioneer 10 & Pioneer 11 fly-bys & 1974
First close-up images of Jupiter
Spectacular images of Galilean moons, esp. Io
Voyager 1 & Voyager 2 fly-bys 1979
Spectacular close-ups of Jovian storm systems
Additional details of most Jovian moons
Galileo atmospheric probe & orbiter 1995
Probe entered clear area in Jupiter’s clouds
Severely crippled yet operated until 21 Sep. 2003
Cassini 2000
The primary mission is to Saturn
Imaged Jupiter during gravity-assist [slingshot] fly-by
Simultaneous observations by Galileo

8. Patterns In Jupiter’s Clouds

9. Jupiter Seen From Far & Near
Earth-based telescope Voyager 1 spacecraft

10. Five Historic Views of Jupiter

11. Jupiter’s Great Red Spot
Solar System champ
Longest lasting storm system Since 1664
Largest storm system ~ 25,000 mi
Basic characteristics
Imbedded in Jupiter’s southern hemisphere
Much higher than surrounding clouds
Circulates counterclockwise
Characteristic of a high pressure system
Similar to high pressure systems in Earth’s atmosphere
Size varies considerably
From ~ 1 to ~3 times Earth’s diameter
Color varies considerably
From deep red to light pink

12. Voyager 2: The Great Red Spot

13. Jupiter & Ganymede: Family Portrait

14. Three Factors Affect Cloud Motions
Insolation Incoming solar radiation
Jupiter’s orbit is ~ 5.2 AU from the Sun
~ 3.7% as much energy per m2 as Earth
Jupiter’s albedo is 0.44 compared to Earth’s 0.39
Effectively reduces solar energy to ~ 3.3% of Earth
Sunlight is absorbed by Jupiter’s atmosphere
Jupiter’s internal heat
Jupiter emits ~ 2x as much energy as from sunlight
Old heat from Jupiter’s formation
New heat from helium condensation
Differential axial rotation
Multiple convection cells in Jupiter’s atmosphere
Drawn out into bands parallel to Jupiter’s equator
Adjacent bands move in opposite directions Zonal winds

15. Spectroscopy of Jupiter’s Atmosphere
Three primary cloud layers
Upper layer ~ 20 km below Tmin
Ammonia (NH3) ice crystals
Middle layer ~ 40 km below Tmin
Ammonium hydrosulfide (NH4SH) ice crystals
Lower layer ~ 60 km below Tmin
Water (H2O) ice crystals
Major cloud features
Belts & zones
Belts are bands of falling air Relatively low & warm
Zones are bands of rising air Relatively high & cool
Brown & white ovals
White ovals lie relatively high in Jupiter’s atmosphere
Smaller versions of the Great Red Spot
Brown ovals lie relatively low in Jupiter’s atmosphere

16. Jupiter’s Upper Atmosphere Structure

17. Jupiter’s (Low) Belts & (High) Zones

18. Jupiter’s Distinctive Cloud Colors
Mostly “Earth tones”
Yellow, brown, pink, red…
Colors vary over time & space
Source of colors
All three cloud layer chemicals are white if pure
Spectroscopy reveals no substantial impurities
Jupiter’s moon Io is extremely active volcanically
Io has abundant sulfur compounds
Io has the same colors as Jupiter’s clouds
Io spews matter into space near Jupiter
Jupiter’s cloud colors may come from Io’s eruptions

19. Jupiter’s Deep Atmosphere: S-L 9
Comet Shoemaker-Levy July 1994
23 visible fragments entered Jupiter’s atmosphere
All less than ~ 1 km in diameter
Entry speed of ~ 60 km ⋅ sec–1 ~ 130,000 mph
Satellites orbit Earth at ~ 8 km ⋅ sec–1
Largest fragment energy equivalent of 6 ⋅ 108 megatons
10,000°C fireballs rose 3,000 km above the clouds
Hopes for eruptions of deep atmospheric layers
Confounded by uncertainties about comet’s composition

20. S-L9: The String of Pearls Comet

21. Comet Shoemaker-Levy 9 Hits Jupiter

22. Jupiter’s Deep Atmosphere: Galileo
Galileo atmospheric probe 7 December 1995
Only spacecraft to enter Jupiter’s atmosphere
Entry speed of ~ 49 km . sec–1 ~ 106,000 mph
Decelerated to ~ 40 km . hr–1 in 3 min. ~ 25 mph
Descended by parachute for ~ 1 hour
Reached ~ – 200 km & + 24 x Earth’s air pressure

23. Jupiter’s Atmosphere Findings
Relatively rare but extremely powerful lightning
Nearly constant winds of ~ 650 km ⋅ hr–1
Much faster than solar-driven high altitude winds
This wind energy must come from Jupiter’s interior
Cloud layer measurements
Galileo Probe’s bad luck ⇒ Entered a clear spot
Traces of NH3 & NH4SH clouds but no H2O clouds
Atmospheric gases
Virtually identical to the Sun
Only ½ expected amount of atmospheric H2O vapor

24. The Galileo Probe Timeline
Probe video

25. Oblate Shape Means a Rocky Core
Distinctly larger equatorial than polar diameter
~ 6.5 % difference for Jupiter
~ 0.34% difference for Earth
Axial rotation spins equatorial material away
Centrifugal effect
Planetary core mass modifies centrifugal effect
Metallic & rocky inner core
Estimated to be ~ 2.6% of Jupiter’s mass
Only ~ 8 x Earth’s mass yet ~ 86% Earth’s diameter
Liquid “ices” outer core
Primarily water (H2O), methane (CH4) & ammonia (NH3)
Estimated to be ~ 3,000 km thick

26. Jupiter’s Four-Layer Internal Structure
Jupiter's Interior

27. Metallic Hydrogen & Magnetosphere
Radio observations of Jupiter 1950’s
Evidence of electric currents
Different types of radio emissions
Thermal emissions Blackbody radiation
Non-thermal emissions
Wavelengths of a few meters Decametric radiation
Wavelengths of a few tenths of a meter Decimetric radiation
Jupiter’s magnetic field is ~ 14 x Earth’s magnetic field
Possible causes
H2 is a liquid metal above atmospheres
Pressure is reached ~ 7,000 km below Jupiter’s clouds
The “gas giant” Jupiter is mostly liquid metallic hydrogen

28. Jupiter’s Immense Magnetosphere
Spacecraft measurements
Pioneer & Voyager
Magnetosphere is ~ km in diameter
~ 210 times Jupiter’s diameter as seen from Earth
~ 2.5 times the Moon’s diameter as seen from Earth
~ 6.3 times the Moon’s area as seen from Earth
Magnetosphere extends beyond the orbit of Saturn
Jupiter’s magnetotail is ~ 6 AU long
Emissions variations repeat every 9h 55m 28s
Assumed to be the core axial rotation rate of Jupiter
Galileo
Suffered extensive radiation damage orbiting Jupiter
Basic characteristics
Jupiter’s magnetosphere is filled with plasma
Solar wind gusts alter Jupiter’s magnetosphere
Magnetosphere’s size varies by a factor of 2

29. Jupiter’s Magnetosphere
A schematic view
A radio view

30. Juno: Jupiter’s Newest Spacecraft
Basic details
Launched 5 August 2011
Six-year planned mission
5 years from Earth to Jupiter Arrives 5 July 2016
1 year science mission
Science objectives
Determine O2 abundance in Jupiter’s atmosphere
Better estimate of Jupiter’s core mass
Precisely map Jupiter’s interior mass distribution
Precisely map Jupiter’s magnetic field
Map variations in atmospheric properties
Jupiter’s polar magnetosphere & aurorae
Measure general relativistic orbital frame-dragging

31. Juno’s Scientific Instruments
Microwave radiometer
Jovian Infrared Auroral Mapper
Magnetometer
Gravity Science
Jovian Auroral Distribution Experiment
Jovian Energetic Particle Detector Instrument
Radio and Plasma Wave Sensor
Ultraviolet Imaging Spectrograph
JunoCam

32. Juno’s Route to Jupiter

33. The Juno Spacecraft at Jupiter

34. The Juno Spacecraft 33 Orbits

35. Juno’s Mission at Jupiter
Polar orbit
Highly elliptical
Spend minimum time in Jupiter’s radiation belts
Planned 33 orbits
Juno de-orbited to crash into Jupiter
Possibility of an extended mission
Mainly an issue of fuel for orientation thrusters

36. Important Concepts: Jupiter
Jupiter data
~ 11.2 times Earth’s diameter
~ 318 times Earth’s mass
~ 2.5 times the mass of all planets
Jupiter as seen from Earth
Distinctly oblate shape
Distinctive cloud bands & storms
Four extremely obvious moons
Distinctive features
Axial rotation period of ~ 10 hours
Solar System’s most colorful clouds
Composed mostly of H & He
Almost same composition as the Sun
Jupiter’s cloud details
Prominent cloud belts & zones
Prominent spots
Great Red Spot
White & brown ovals
Jupiter’s deeper atmosphere
Comet Shoemaker-Levy 9
23 fragments < 1 km in diameter
Galileo Probe spacecraft
1 tiny spacecraft for ~ 1 hour
Jupiter’s four-layer internal structure
Ordinary gaseous hydrogen & helium
Helium & liquid metallic hydrogen
Liquid “ices” (H2O, CH4 & NH3)
Rocky & metallic core
Jupiter’s magnetosphere
Magnetic field strength ~ 14 x Earth’s
Circulating liquid metallic hydrogen
Very fast axial rotation
Magnetic field size
Width of ~ 210 x Jupiter’s diameter
Length of ~ 6 AU (past Saturn’s orbit)
Deflates quickly due to solar wind