Title: Chapter 11: Jupiter Giant of the Solar System
1Chapter 11 JupiterGiant of the Solar System
- Differences from terrestrial planets
- Atmosphere
- Structure and Composition
- Magnetosphere
- Satellites
2Galileo 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.
3After 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.
4Jupiter, 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.
5Planet PropertiesRelative Mass of Planets
6Planet PropertiesAverage Distance from Sun
7Planet PropertiesPlanetary Densities
8Chemistry 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
9Jupiter 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
10Two 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
11View 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
12Viewing 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.
13View 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.
14Voyager Missions Path through the Solar System
15Jupiter Highlights of Voyager Mission
- Found 3 new satellites.
- Io - active volcanism.
- Discovered zones of aurora.
- Discovered rings.
16Galileo ProjectThe Moon, Asteroids, Jupiter, Io,
and Europa
- Launched in 1989 from space shuttle Atlantis.
- Orbiter and atmospheric probe
17Galileo 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.
18Cassinis View of Jupiter
- Jupiter in three wavelengths
- left blue (visible)
- middle ultraviolet
- right infrared
19Interior 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.
20Rotation 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.
21Jupiters Internal Structure
22Jupiters Interior
23Jupiter 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.
24Questions 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?
25Atmosphere
26Atmosphere 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.
27Atmosphere 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.
28Jupiters Heat Engine
Atmospheric motions appear to be driven by
internal and external heating.
infrared wavelengths
visible wavelengths
29Jupiter 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.
30Convection 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.
31More 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.
32Atmosphere 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.
33Global 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)
34Belts and Zones
- These drawings indicate both the horizontal
(left) and vertical (right) circulation in the
clouds of Jupiter. (NASA)
35Belts and Zones
- Wind flow patterns in Jupiters belts and zones
36Cloud 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
37Jupiters 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.
38Atmosphere 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.
39Storms 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).
40Great Red Spot
41Great Red Spot
HST images of Great Red Spot over a seven year
period.
42Storms White Ovals
Collections of white clouds, grouped together
into an oval shape commonly found in all regions
of Jupiters atmosphere.
43White 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
45Polar 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
46Questions 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?
47Jupiters 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.
48Magnetosphere
- 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.
49Model of Jupiters Magnetosphere
- Model of magnetosphere showing interaction with
solar wind and Io torus.
50The 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.
51The Io Torus
52Jupiters 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.
53Aurora
54Jupiter in Radio Wavelengths
- View of radio wavelength radiation from particles
trapped in Jupiters magnetic field.
55Questions 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.
56Hydrosphere
- 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.
57Biosphere
- 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.
58Jupiters Moons
59Transits of Jupiters Moons
60Jupiters 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.
61The 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
62The 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)
63The 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
64Why 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
65Size, 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.
66Galilean Moons
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68Galilean Moons in Cross-Section
69Io from Pioneer
70Io
71Io
72Io
- 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).
73Volcanic 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.
74Volcanic Vents on Io
75Recent Volcanic Activity on Io
76Io 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)
77Three Icy Moons
Callisto Ganymede Europa
78Europa
79Europa
- 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.
80Ruddy "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.
81Europas Surface A Close-up View
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83Surface 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
84Europas 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.
85Europa Surface and Interior
86Ganymede
87Ganymede
- 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.
88Moon Size Comparison
89Ganymedes 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.
90Ganymede-Surface Features
91Ganymedes Interior
92Callisto
93Callisto
- 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.
94Callistos 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.
95Callistos 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.
96Comparison of Galilean Satellites
97Questions 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?
98Jupiters 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.
99Questions Rings
- How was Jupiters ring discovered?
- Describe the ring
- location,
- particle size range,
- particle density,
- particle color,
- source of ring material.
100Jupiter
- 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.
101Overview 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.
102Overview 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.
103Overview 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
104Jupiters Magnetosphere