The Jovian Planets,
Part I
Jupiter
JUPITER
The God Of Thunder and Sky
Physical Data
 Diameter:
71,400 km (11.19 Dearth)
 Mass: 1.899x1030 g (317.9 Mearth)
 Density: 1.33 g/cm3
 Rotation Period: 9.92 hours (radio)
o
 Tilt of Axis: 3
 Surface Temperature: 130 K
Physical Data
 Orbital
Semi-Major Axis: 5.203 AU
 Orbital Period: 11.86 years
o
 Orbital Inclination: 1.3
 Orbital Eccentricity: 0.048
 Surface Gravity: 2.53 Earth gravity
 Satellites: 63 as of 2011
 Magnetic Field: 19,000 times greater than
Earth’s
Jupiter’s Interior
ATMOSPHERE
LIQUID
MOLECULAR HYDROGEN
METALLIC
HYDROGEN
IRON
SILICATE
CORE
Jupiter’s Atmosphere
 90%
Hydrogen
 10% Helium
 Small amounts of:
Methane
Ammonia
Ethane
Water
Jupiter’s Atmosphere
Clouds composed of:
 Ammonia
 Ammonia
Hydrosulfide
 Hydrogen
Sulfide
 Water Vapor
The Surface Temp.
o
is 150 K (-190 F).
Jupiter’s Atmosphere
L
H
L
H
L
H
L
BELTS:
 Usually brown or red
 Low-pressure regions
of sinking gas
 Lower than zones
ZONES:
 Usually yellow-white
 High-pressure regions
of rising gas
 Higher than belts
JET STREAMS blow at
the boundaries
Jupiter’s Atmosphere
The Great Red Spot
 Huge
anti-cyclone (goes
counterclockwise in
Southern Hemisphere)
 Circulation Period: 6 days
 Known for 300 years
 It is 14,000 km wide and
40,000 km (three Earth
diameters!) long
Jupiter’s Atmosphere
Hot Surface Temperature:
 The temperature at Jupiter’s surface (cloud
tops) is about 130 K
 Calculations say it should be 107 K
 Discrepancy because Jupiter’s interior
radiates 2.5x as much heat as it receives
from the Sun
 Jupiter is still slowly contracting
Jupiter’s Magnetic Field
 Strongest
magnetic field in the solar system
o
 Tilted 15 from the axis of rotation
 Highly flattened due to rapid rotation
 Distorted
 The moon Io, revolves
in the magnetosphere,
and matter from it
accumulates in a torus
Jupiter’s Magnetic Field
Matter in the Io torus
stimulates the
emission of radio
bursts
 This radiation called
decametric radiation
 Decametric bursts can
be short (S-bursts) or
long (L-bursts)

L-burst
S-Burst
S-Burst
(slowed down)
Jupiter’s Rotation Periods
 Jupiter
is a differential rotator
 This means not all parts of Jupiter’s surface
rotate at the same rate
 Equatorial rotation rate
(System I) = 9h50m30.003s
 Polar rotation rate (System
II) = 9h55m40.632s
Jupiter’s Rotation Periods
 The
most widely used rotation period is
System III
 This is the rate at which the interior rotates
as observed through the radio emissions
 Radio rotation rate (System III) =
9h55m30.003s
Jupiter’s Rings
 Found
by Voyager I
fly-by
 Main ring extends
from 1.72-1.81
Jupiter radii from
center of planet
 Brightest part is
about 6,000 km
wide
Jupiter’s Moons
 At
least 16
 The four largest were discovered by Galileo
and are now referred to as the “Galilean
Satellites”:
Io, Europa, Ganymede, Callisto
“I Eat Green Centipedes”: How to
remember their order and relative density
(i.e. Io is closest and most dense)
Jupiter’s Moons
IO
EUROPA
size of
our Moon
GANYMEDE
CALLISTO
size of
Mercury
Jupiter’s Moons
IO
dense
core
active sulfur
crust
rocky
interior
molten
silicate
GANYMEDE ice/rock
crust
rocky or
muddy
core
EUROPA
dense
core
subsurface
oceans?
CALLISTO
thick
ice/rock
crust
rocky or
muddy
core
water/ice
mantle
ice/rock
crust
Jupiter’s Moons
IO
Densest Galilean moon
 Most volcanically active
body in the Solar System
 Fresh surface, no impact
craters
 Inside Jupiter’s
magnetosphere:
decametric emission

Jupiter’s Moons
Europa
Very little surface
relief
 Smoothest body in the
Solar System
 Cracked ice surface
features

Jupiter’s Moons
Ganymede
Largest moon in the
Solar System
 Surface is “Moonlike”, i.e. cratered and
has maria
 Made of 50% water
 Little surface relief

Jupiter’s Moons
Callisto
Perhaps the most
heavily cratered body
in the Solar System
 Lowest density of all
the Galilean satellites
(more than 50% water
ice)
 Little surface relief
