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Title: Chapter 11: Jupiter Giant of the Solar System


1
Chapter 11 JupiterGiant of the Solar System
  • Differences from terrestrial planets
  • Atmosphere
  • Structure and Composition
  • Magnetosphere
  • Satellites

2
Galileo spacecraft11/05/02
  • As Galileo approaches Jupiter on Nov. 5, 2002
    UT
    (1019 p.m. Nov. 4, PST),
  • the spacecraft will visit three intriguing
    features of the giant planet's neighborhood for
    the first time
  • a small moon named Amalthea,
  • a dusty ring, and
  • the inner region of Jupiter's high-energy
    magnetic environment.

3
After completing this chapter, you should be able
to
  • compare the general physical properties of
    Jupiter/Earth.
  • compare orbital and rotational properties of
    Jupiter/Earth.
  • describe atmosphere, hydrosphere, lithosphere,
    magnetosphere, and biosphere of Jupiter and
    compare to Earth.
  • describe Jupiter's cycle of visibility as seen
    from Earth.
  • explain why Jupiter's atmosphere is so different
    from Earth's.
  • describe Jupiter's ring system.
  • describe physical properties/origin of Galilean
    satellites.
  • explain the origin of Io's volcanoes, Europas
    surface.

4
Jupiter, Saturn, Uranus, NeptuneThe Jovian
Planets
  • Outer or giant or jovian planets.
  • Over 1400 Earths could fit inside Jupiter
  • Composed primarily of lighter ices, liquids,
    gases.
  • Do not have solid surfaces more like vast,
    ball-shaped oceans with much smaller, dense cores
    at their centers.
  • Extensive satellite and ring systems.

5
Planet PropertiesRelative Mass of Planets
6
Planet PropertiesAverage Distance from Sun
7
Planet PropertiesPlanetary Densities
8
Chemistry of Giant Planets
  • Jupiter Saturn nearly same chemical makeup as
    Sun.
  • primarily hydrogen and helium
  • by mass 75 hydrogen, 25 helium
  • Gas compressed in interior until hydrogen
    liquifies.
  • Uranus and Neptune are smaller, attracted
    less hydrogen and helium.
  • All have interior core composed of rock, metal,
    and ice approximately 10 x mass of Earth.
  • Chemistry dominated by hydrogen, oxygen
    in form of H2O (water and water ice)
  • Atmospheres hydrogen-based gases CH4
    (methane) or NH3 (ammonia) or more complex

9
Jupiter Fact Sheet
  • Diameter 142,800 km (88,736 miles, 11.2 x
    Earth, 1/10 x Sun)
  • Mass 318 x Earth (1/1000 x Sun)
  • Density 1.33 g/cm3 (H2O1, Earth 5.5)
  • Length of Day 9 hrs 55 min
  • Length of year 12 Earth years
  • Average Distance from Sun 5.2 AU (483
    million miles)
  • Tilt of Axis 3.1o
  • Escape Velocity 60 km/s
  • Distance across the Great Red Spot
    40,000 km (2xEarths diameter)
  • Temperature at Cloud Tops 124 K
  • Temperature at core 20,000 K
  • Rings 1, very thin
  • Satellites 28 known

10
Two Object Solar System?
  • Jupiter has more mass than all of the other
    objects in solar system combined
    (ignoring the Sun).
  • Its gravity
  • moves comets into new orbits,
  • helps keep asteroids in place,
  • may have created the Oort Cloud of comets,
  • controls a system of 28 moons
  • Its tidal pull has
  • kept Io molten for billions of years
  • probably provided Europa with a deep, liquid
    ocean
  • Its atmosphere has
  • storm swirls larger than the entire Earth
  • winds that move at over 400 km/hr faster than
    interior

11
View from Earth
  • Closest of Jovian planets to Earth
    ( 4 AU at its nearest).
  • Fourth brightest object
  • brightest when
    near
    opposition
  • up to 50 across
  • Earth-based telescopes
  • distinct, multi-colored bands across surface
    large reddish area in southern hemisphere
  • satellites
  • intense bursts of radio energy

12
Viewing Jupiter
  • Oppositions occur every 399 days, so Jupiter is
    nearest the Earth and brightest once each year.
  • Because of its great distance from the Earth,
    its brightness does not vary greatly.
  • It moves eastward through approximately one
    constellation of the zodiac each year, because it
    takes just under 12 years to orbit the Sun.
  • Jupiter's four large moons (Galilean satellites)
    are easily visible through a small telescope
    and even binoculars.
  • The changing positions of these moons can
    be seen during one night's
    observations.

13
View from Space
  • Pioneer 10 and Pioneer 11 (launched 1972, 1973)
    were first spacecraft to visit outer
    planets.
  • navigate asteroid belt
  • study charged particles and magnetic field
  • photograph surface
  • Voyager 1 and Voyager 2 launched in 1977.
  • Designed to study Jupiter and Saturn
    both still transmitting data as they travel
    toward boundary of solar system and into
    interstellar space.
  • Voyager 2 passed
  • within 80,000 km of Uranus
    (within 16 km of planned
    target) and
  • 5000 km above Neptunes clouds.
  • Galileo launched in 1989 arrived December, 1995.

14
Voyager Missions Path through the Solar System
15
Jupiter Highlights of Voyager Mission
  • Found 3 new satellites.
  • Io - active volcanism.
  • Discovered zones of aurora.
  • Discovered rings.

16
Galileo ProjectThe Moon, Asteroids, Jupiter, Io,
and Europa
  • Launched in 1989 from space shuttle Atlantis.
  • Orbiter and atmospheric probe

17
Galileo Highlights
  • Discovery of an intense new radiation belt
    approximately 50,000 km (31,000 miles) above
    Jupiter's cloud tops.
  • Jovian wind speeds in excess of 600 km/hr (gt 400
    mph) detected.
  • Far less water was detected in Jupiter's
    atmosphere than estimated from earlier Voyager
    observations and from models of the Comet
    Shoemaker-Levy 9 impact.
  • Far less lightning activity than anticipated
    (about 10 of that found in an equal area on
    Earth). Individual lightning events, however,
    are about ten times stronger on Jupiter than the
    Earth.
  • Helium abundance in Jupiter is very nearly the
    same as its abundance in the Sun (24 compared to
    25).
  • Extensive resurfacing of Io's surface due to
    continuing volcanic activity since the Voyagers
    flew by in 1979.
  • Preliminary data support the tentative
    identification of intrinsic magnetic fields for
    both Io and Ganymede.
  • Evidence for liquid water ocean under Europa's
    surface.

18
Cassinis View of Jupiter
  • Jupiter in three wavelengths
  • left blue (visible)
  • middle ultraviolet
  • right infrared

19
Interior Structure
  • Rough model of Jupiter's internal structure can
    be deduced from the planet's
  • mass
  • density
  • rotation
  • shape
  • Jupiter appears to be highly differentiated with
    a relatively small rocky and/or metallic core,
    perhaps the size of Earth and
    with 10 x Earths mass.

20
Rotation Rate
  • No solid surface features to observe.
  • Cloud features in upper atmosphere move at
    different rates, depending on latitude, activity.
  • Near equator 9 hr 50 m period
  • Closer to poles 9 hr 55 m period (globe)
  • Magnetosphere-related radiation
  • 9 hr 55 m period
  • Observed flattening too small for planet composed
    entirely of hydrogen and helium.

21
Jupiters Internal Structure
22
Jupiters Interior
23
Jupiter Composition
  • Interior composition Mostly
    simple molecules of hydrogen in liquid form.
  • Under the cloud layers, as the
    pressure increases, the hydrogen
    changes to liquid hydrogen.
  • Further increases in pressure change liquid
    hydrogen to liquid metallic hydrogen.
  • Core composition heavier, rocky and
    metal elements.

24
Questions Internal Structure
  • What is differential rotation?
    How is it observed on Jupiter?
  • How do observations of magnetosphere allow
    astronomers to measure the rotation rate of a
    planets interior?
  • What does Jupiters degree of flattening tell us
    about its interior?
  • What is thought to lie beneath Jupiters clouds?
  • Why do we think this?

25
Atmosphere
26
Atmosphere Origin and Evolution
  • Jupiter's atmosphere is thought to be a remnant
    of Solar System formation.
  • Evolved very little since initial formation.
  • That is why planetary scientists feel it is
    extremely important to study it.
  • It may be somewhat similar to
    Earth's primary atmosphere.

27
Atmosphere Composition
  • Jupiter has an extremely dense atmosphere.
  • Atmospheres composition is more like
    the Sun than any of the terrestrial
    planets.
  • Hydrogen - 86.
  • Helium - 13.
  • Methane (CH4) - trace.
  • Ammonia (NH3) - trace.
  • Water (H2O) - trace.
  • Believed that the bulk of the interior
    has similar
    composition.
  • This property makes it quite different than the
    terrestrial planets and explains its relatively
    low bulk density.

28
Jupiters Heat Engine

Atmospheric motions appear to be driven by
internal and external heating.
infrared wavelengths
visible wavelengths
29
Jupiter Heat Sources
  • External
  • Solar energy
  • Internal
  • Primordial heat
    generated during
    formation by
    collapse of materials onto core.
  • Contraction slow
    shrinking of planet after formation
  • Jupiter radiates about 1.6 times as much
    energy into space as it receives
    from the Sun.

30
Convection and Internal Motions
  • The drawing illustrates a kind of global motion
    typical of motions in both the atmosphere and the
    interior of a planet.
  • Material rises from warmest region, and moves in
    a roiling motion (like boiling of a pot).
  • Shown are three different cells of activity in
    the atmosphere where the air turns over (depicted
    by red sheets).
  • In the interior of Jupiter, the liquid
    layers are warm enough to move in this fashion.

31
More on Interior Motions
The drawing shows layered cylinders of material,
in motion, rolling in different directions. This
pattern may be in operation with the tips of
cylinders corresponding to the striped pattern of
clouds seen in the atmosphere.
32
Atmosphere Circulation
  • Rapid rotation rate causes planet's atmosphere to
  • bulge at the equator
  • be flattened at the poles.
  • Rotation rate is greater at the equator than
    at the poles (differential
    rotation).
  • Jupiter's rapid rotation deflects rising and
    sinking currents of gases (Coriolis effect) into
    strong zonal flows of winds
    moving east and west.
  • somewhat like super jet streams on Earth.
  • The dark belts are bands of sinking, cooler
    gases, and the light zones are bands of rising,
    warmer gases.
  • equivalent to Earths high and low pressure
    systems.

33
Global Circulation
  • Circulation of the Jovian atmosphere. The global
    circulation pattern shown here indicates the
    location and designations of the belts and zones
    in Jupiter's cloud layer. (NASA)

34
Belts and Zones
  • These drawings indicate both the horizontal
    (left) and vertical (right) circulation in the
    clouds of Jupiter. (NASA)

35
Belts and Zones
  • Wind flow patterns in Jupiters belts and zones

36
Cloud Layers
  • 3 different layers of clouds or cloud-decks.
  • Composition of cloud-decks (outer to inner)
  • 1st ammonia.
  • 2nd ammonium hydrosulfide
    (ammonia sulfur)
  • 3rd ordinary water clouds

37
Jupiters Cloud Patterns
  • Pattern of clouds in white, brown, and orange.
  • Other shapes include eddy shapes, white ovals,
    brown ovals, and brown barges.
  • Eddies and white ovals are outlined in this
    picture.
  • Form in stripes and move across face of Jupiter.
  • Stripes similar to those found on all the giant
    planets.

38
Atmosphere Colors
  • Colors are caused by trace amounts of organic,
    sulfur, and/or hydrogen molecules which absorb
    sunlight at different wavelengths.
  • A great deal of turbulence occurs at the
    interface between belts and zones.
  • These are regions of large jovian storms.

39
Storms The Great Red Spot
The Great Red Spot is thought to be a hurricane
which has been raging on Jupiter for well over
300 years. High-pressure region with high, cold
cloud tops (CCW rotation).
40
Great Red Spot
41
Great Red Spot
HST images of Great Red Spot over a seven year
period.
42
Storms White Ovals
Collections of white clouds, grouped together
into an oval shape commonly found in all regions
of Jupiters atmosphere.
43
White Spots vs. GRS
  • High pressure storms.
  • Compared to Great Red Spot (GRS)
  • Lower in the atmosphere than GRS.
  • Smaller than GRS.
  • Do not last as long as GRS.

44
Storms Brown Barges
  • Low pressure storms.
  • Lowest in the atmosphere.
  • actually holes in atmosphere
  • Appear around 20oN latitude.
  • Short-lived compared to GRS

45
Polar Vortex
  • Jupiter has a cold vortex in its upper atmosphere
    over its north pole resembling the vortex over
    Earth's south pole that enables depletion of
    Earth's stratospheric ozone. A sharp
    temperature drop, compared to surrounding air
    masses, creates an eastward wind that tends to
    keep the polar atmosphere, including the
    stratospheric haze, isolated from the rest of the
    atmosphere.
  • A cold air mass, that maintains a roughly
    hexagonal shape, extends vertically from
    Jupiter's stratosphere down into the next-lower
    layer of the atmosphere and rotates at a rate
    that takes about 300 days to complete a full
    circle.
  • Image credit NASA/JPL/HST/University of Hawaii

46
Questions Atmosphere
  • Why has Jupiter retained most of
    its original atmosphere?
  • Explain a theory that accounts for the
    unexpectedly high temperatures observed
    at Jupiters cloud tops.
  • List some similarities and differences between
    Jupiters belts, zones, and spots
    and weather systems on
    Earth.
  • What is the Great Red Spot?
  • What is the cause of the colors
    in Jupiters atmosphere?

47
Jupiters Magnetosphere
  • Jupiter's magnetosphere is biggest thing in
    entire solar system.
  • Big enough to hold all of Jupiter's moons or Sun
    itself.
  • Tail extends to Saturn.
  • From Earth, would appear as large as the full
    Moon.
  • Extremely powerful (and deadly) radiation belts
    circle the planet, similar to Earths Van Allen
    radiation belts.
  • Region found by Galileo in uppermost atmosphere
    strength 10 x Earths Van Allen Belts
  • Donut-shaped cloud inside the magnetosphere
    coincides with Io.
  • Jupiter lights up with very beautiful aurora.
  • Jupiter also makes radio signals and other waves.

48
Magnetosphere
  • Jupiter has an extensive magnetosphere
    about 10 time stronger than the
    Earth's.
  • Discovered from Earth by detection
    of its strong radio transmissions.
  • This strong magnetic field is probably caused by
  • very rapid rotation of
  • Jupiters liquid metallic hydrogen core.
  • The magnetic field extends far
    into space in a sheet structure
    centered on the plant's
    equator.

49
Model of Jupiters Magnetosphere
  • Model of magnetosphere showing interaction with
    solar wind and Io torus.

50
The Io Torus
The Io plasma torus is the result of material
being ejected from Io's volcanoes and swept up by
Jupiter's rapidly rotating magnetic field.
Spectroscopic analysis indicates that the torus
is composed primarily of sodium and sulfur atoms.
51
The Io Torus
52
Jupiters Aurora
  • Very powerful energy source. Produces much more
    power (1,000,000 MWatts) than the Earth's aurora
    (1000 MWatts).
  • For comparison, a large city uses about 10,000
    MWatts.
  • Significantly impacts atmosphere.
  • Unlike the Earth, the Jovian aurora is thought to
    come from two places
  • from the moon Io, and
  • from currents carrying particles from somewhere
    deeper in Jupiter's magneto-tail.

53
Aurora
54
Jupiter in Radio Wavelengths
  • View of radio wavelength radiation from particles
    trapped in Jupiters magnetic field.

55
Questions Magnetosphere
  • What is responsible for Jupiters enormous
    magnetic field? Why is it so much larger than
    Earths?
  • How was Jupiters magnetic field discovered?
  • Compare Jupiters magnetic field to
    Earths magnetic field.
  • Include generation, field strength, aurora,
    trapped particles, interaction with moons.

56
Hydrosphere
  • Near the top of Jupiter's atmosphere,
    water is frozen, but below the
    cloud tops the temperature and pressure gradually
    increase.
  • There is probably a level at which
    liquid water is stable.
  • So, there should be a fair amount
    of water in the jovian
    atmosphere.
  • Results from the Galileo atmospheric probe
    indicated less water than predicted.
    These results are still being
    analyzed.

57
Biosphere
  • Of course, none is known, but some have
    speculated about the possibility of life existing
    at hospitable levels
    in the jovian atmosphere.
  • However, strong down drafts are likely to destroy
    fragile organic compounds soon
    after they form.

58
Jupiters Moons
59
Transits of Jupiters Moons
60
Jupiters Moons
  • Jupiter has 28 known moons.
  • Most are rather small, but the four largest
    (discovered by Galileo in 1609)
    are as large or larger
    than the Earth's Moon.
  • The largest (Ganymede) is larger than
    the planets Mercury and Pluto.
  • The comparative features of the Galilean Moons
    mimic to some extent the properties of the
    planets in the Solar System.
  • The jovian satellite system is itself somewhat
    like a miniature solar system.

61
The Moons of Jupiter
  • 28 known moons
  • 4 very small moons orbiting inside the
    orbit of Io
  • 4 large Galilean moons
  • 8 small moons
  • 4 in eccentric, inclined orbits,
    11 million km from Jupiter
  • 4 in eccentric, retrograde orbits,
    22 million km from Jupiter
  • 12 recently discovered small moons in inclined,
    eccentric, mainly retrograde orbits, 10-25
    million km from Jupiter

62
The Galilean Satellites
These are the four moons discovered by Galileo,
shown in correct relative size. Ganymede is the
largest satellite in the solar system.. (NASA)
63
The Galilean Satellites
  • Io, Europa, Ganymede, Callisto are
  • comparable in size to Earths Moon,
  • move in nearly circular orbits about Jupiter.
  • Jupiters rotation slowing due to tidal drag of
    Galilean satellites, and satellites orbits
    slowly increasing.
  • Io, Europa, and Ganymede locked in 124 orbital
    resonance
  • Callisto approaching 2x Ganymedes period
    (1248)
  • System similar to scaled-down solar system
  • As distance from Jupiter increases,
    moons sizes increase,

    moons densities decrease
  • compositions grade from rock/iron to rock/ice

64
Why study Jupiter and its moons?
  • The Sun's inner planets -- Mercury, Venus, Earth
    and Mars -- are rocky worlds much
    denser than the gassy and icy planets
    from Jupiter on out.
  • Likewise for Jupiter's four large moons
  • Io, the innermost, is mainly dense rock and iron,
  • while Ganymede and Callisto, the 2 outermost, are
    mixtures of rock ice,
  • and Europa completes a gradient in between.
  • Amalthea orbits about halfway between Jupiter and
    Io.
  • If it is dense, that could fit a theory that
    primordial Jupiter, like the Sun, gave off enough
    heat to prevent volatile, lightweight
    ingredients, such as water ice, from condensing
    and being incorporated into the orbiting bodies
    forming closest to it.
  • Knowing Amalthea's density might help pin down
    whether the origin of moons around Jupiter
    resembled the origin of planets around the Sun.
  • http//www.jpl.nasa.gov/releases/2002/release_2
    002_199.cfm

65
Size, Mass, Density, Composition, Formation
  • The Galileo orbiter to pass 160 km (99 miles)
    above Amalthea's surface.

    By measuring the strength of
    Amalthea's gravity tugging
    at the spacecraft,
    researchers
    intend to determine the moon's mass.

    Since previous orbits
    have provided a good estimate of its size,
    learning its mass will allow a calculation of its
    density, an important clue to its composition.

66
Galilean Moons
67
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68
Galilean Moons in Cross-Section
69
Io from Pioneer
70
Io
71
Io
72
Io
  • Innermost Galilean satellite.
  • Composition is mostly rocky,
    almost no volatiles.
  • Driest place in the outer Solar System.
  • No impact craters,
    surface renewed to 300
    feet every million years.
  • Surface composition is sulfur lava and SO2.
  • Active volcanoes erupting S, SO2, sodium
    compounds.
  • Extremely violent eruptions 10 x greater than
    Earth's.
  • Volcanoes eject matter into Jupiter's magnetic
    field radiation belts (10,000
    tons/second).

73
Volcanic Activity on Io
  • Source of geological activity on Io is tidal
    effect of Jupiter on Io as it orbits the planet.
  • These tidal forces are so large that Io's surface
    is pulled upwards and downwards by hundreds of
    meters in each rotation.
  • Tidal squeezing causes the interior to melt,
    causing volcanic activity.
  • Heat flow is 30 times greater than
    Earth's.
  • 1/3 Earths size
  • A very thin (10-7 Earth's) atmosphere of SO2.

74
Volcanic Vents on Io
75
Recent Volcanic Activity on Io
76
Io Torus
Ground-based telescope on Earth, shows the cloud
of sodium atoms surrounding Io as it orbits
Jupiter. Sizes of Jupiter, Io (dot inside
cross-hair), and Io's orbit are all to correct
relative scale. (B. A. Goldberg, G. W.
Garneau, S.K. LaVoie, JPL)
77
Three Icy Moons
Callisto Ganymede Europa
78
Europa
79
Europa
  • Young smooth surface with very few craters.
  • Perhaps an icy surface and a rocky
    interior.
  • Cracks are observed, thought to be ridges of
    fresh ice on the surface.
  • May be an ocean of liquid water
    below the icy surface.
  • A thin atmosphere of oxygen was detected by
    Galileo spacecraft.

80
Ruddy "Freckles" on Europa Suggest 'Lava Lamp'
ActionOctober 30, 2002
  • Reddish spots on the icy surface of Europa may
    indicate pockets of warmer ice rising from below.
    This upwelling could provide an elevator ride to
    the surface for material in an ocean beneath the
    ice, say scientists studying data from NASA's
    Galileo spacecraft.
  • "Europa acts like a planetary lava lamp, carrying
    material from near the surface down to the ocean,
    and, if they exist, potentially transporting
    organisms up toward the surface," said Dr. Robert
    Pappalardo, a planetary scientist at the
    University of Colorado, Boulder.

81
Europas Surface A Close-up View
82
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83
Surface of Europa
  • Conamara Chaos region on Europa taken by NASA's
    Galileo spacecraft shows an area where the icy
    surface has been broken into many separate plates
    that have moved laterally and rotated.

Trailing side of Europa
84
Europas Evolution
  • Europa, like Io, is heated internally by the
    tidal tug-of-war with Jupiter.
  • Since Europa is further
    from Jupiter than Io, the tidal
    effect is less dramatic.
  • In the case of Europa, the effect of the tides
    induced by Jupiter is to heat the interior of
    Europa sufficiently to keep the surface soft.
  • Thus, no vertical relief features can
    survive for long on Europa's surface, explaining
    its smooth appearance.

85
Europa Surface and Interior
86
Ganymede
87
Ganymede
  • Largest satellite in the
    Solar System.
  • Composed of a mixture of
    rock and water ice.
  • Probably a very thick crust
    of water ice.
  • Shows combination of cratered and grooved
    terrain.
  • Changing ice phases may have caused it to expand
    3.5 billion years ago forming grooves and ridges.

88
Moon Size Comparison
89
Ganymedes Features
  • Largest moon in the Solar System (larger than
    Mercury).
  • Largely covered by a frozen water ocean.
  • Portions of surface look young geologically
    portions look old.
  • Large grooves in surface crust broken into
    fragments.
  • Evidence for past plate tectonic activity first
    conclusive evidence of plate tectonics in the
    Solar System beyond the Earth.
  • Weak magnetic field, first detected for satellite
    in this Solar System.

90
Ganymede-Surface Features
91
Ganymedes Interior
92
Callisto
93
Callisto
  • Outermost of the Galilean Satellites.
  • Very old surface,
    covered with craters and
    impact basins.
  • Lowest density of the large moons.
  • Composed of perhaps 50 water ice.
  • Shows the least amount of tectonic activity.
  • It may have some internal differentiation
    caused by radioactive decay.

94
Callistos Cratered Surface
  • Callisto has the most heavily cratered surface of
    the four Galilean moons.
  • The number of craters imply that the surface of
    Callisto is 4 billion years
    old.

95
Callistos Surface
  • Similar in appearance to Ganymede, more craters
    and fewer fault lines.
  • Most obvious feature huge series of concentric
    ridges surrounding two large basins.
  • Ridges resulted from impact with asteroid or
    comet. Up-thrust ice partially melted
    resolidified quickly, before the ripples
    subsided.
  • Today, ridges and rest of crust are frigid ice,
    showing no obvious signs of geological activity.
  • The density of impact craters on the Valhalla
    basin indicates that it formed 4 billion years
    ago.

96
Comparison of Galilean Satellites
97
Questions Moons
  • Compare sizes of Galilean moons terrestrial
    objects.
  • Describe the variation in density as a function
    of distance from Jupiter for the Galilean moons.
  • How does the amount of cratering vary among the
    Galilean moons? Does it depend on their
    location? If so, how?
  • What is the source of all the activity observed
    on Jupiters Galilean satellites?
  • Why is there speculation that the Galilean moon
    Europa might be an abode for life?
  • Water is relatively uncommon among the
    terrestrial planets. Is it common among the
    moons of Jupiter?

98
Jupiters Ring
Discovered in 1979 by Voyager missions inside
orbit of innermost moon few 1000 km across, few
10s km thick in equatorial plane made of small
grains of rocky material, albedo 0.05, no ice.
99
Questions Rings
  • How was Jupiters ring discovered?
  • Describe the ring
  • location,
  • particle size range,
  • particle density,
  • particle color,
  • source of ring material.

100
Jupiter
  • Largest planet in the solar system.
  • Primarily composed of hydrogen and helium.
  • Rapid, differential rotation.
  • Internal structure and heat source.
  • Thick atmosphere with 3 main cloud layers.
  • Layers arranged into bands of bright zones and
    darker belts that cross surface parallel to
    equator and are the result of convection and
    rapid planetary rotation.
  • Stable zonal E-W wind flow underlying
    belts/zones.
  • Long term weather patterns/storms
    Great Red Spot, white ovals, brown ovals.
  • Magnetosphere
  • 28 known satellites
  • Galilean satellites
  • Small, dark, faint rings discovered by Voyager
    1.

101
Overview of Jupiter from Earth
  • Jupiter is a giant planet located fifth from Sun.
  • Its mass of 318 x Earths and diameter of 11
    Earth diameters yield an average density of 1.3 x
    water.
  • It appears through ground-based telescopes as a
    gas giant flattened by rapid rotation, with
    reddish and whitish belts and zones. Within one
    zone in S-hemisphere is the Giant Red Spot
    (2xEarth). Many satellites visible four
    largest called Galilean satellites.
  • Ground-based radio telescopes found synchrotron
    radiation, indicating the presence of a strong
    magnetic field.
  • Other observations show that Jupiter emits 2x
    energy it captures from Sun. Excess energy from
    internal heat from time of Jupiters formation.

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Overview of Jupiter from Space
  • Pioneer and Voyager probes show highly turbulent,
    stormy atmosphere, lightning, and aurorae.
  • Confirmed expected presence of hydrogen and
    helium as the main constituents of the planet.
  • Atmosphere hydrogen, helium, ammonia, methane
  • Voyager discovered a ring composed of small,
    dark, rocky grains.
  • Magnetosphere mapped extensive and tilted 100 to
    rotation axis.
  • Interior structure modeled as a rocky core
    surrounded by a region of liquid metallic
    hydrogen. Believed that this material behaves
    like a metal and that its rotational and
    turbulent convection motions produce the planets
    magnetic field.

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Overview of Jupiters Moons
  • 28 known satellites
  • Four largest, called the Galilean satellites,
    form a miniature solar system around Jupiter .
  • Io
  • volcanic
  • gases form a cloud around Io and its orbit
    creates aurora torus
  • Europa
  • straight-line features in icy methane and ammonia
    surface
  • possible water ocean beneath surface
  • Ganymede
  • largest satellite in solar system, first observed
    with magnetic field.
  • cratered, icy crust with evidence past plate
    tectonics activity
  • Possible water ocean beneath surface
  • Callisto
  • old, icy, saturated with craters and a large
    multi-ringed basin

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Jupiters Magnetosphere
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