Transcript Jovian Planets

Jovian Planets
Composition
• Jupiter is composed
of 97% H and He
• Saturn is composed
of 90% H and He
• Uranus and Neptune
are CH4 H2O and NH3
• Neptune and Uranus
are more dense than
Jupiter and Saturn
• Jupiter is more dense
than Saturn
Jupiter
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a = 5.20 AU
R = 11.2REarth
M = 318MEarth
ρ = 1.33 g/cm3
Saturn
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a = 9.54 AU
R = 9.4REarth
M = 95.2MEarth
ρ = 0.70 g/cm3
Inside Jupiter
• Formed around
rock and metal
core weighing
about 10x Earth
• The rest is H,
compressed into
strange phases
Inside Other Jovian Planets
Similar compositions, but less mass means
less of the strange liquid and metallic H
(Uranus and Neptune have only gaseous H)
Magnetic Fields
• Rotating
Metallic H
creates strong
field
• ~20,000x as
strong as
Earth’s
Jupiter’s Colors
• Yellow = NH3
• Rust = (NH4)SH
• Blue/White = H2O
Neptune
CH4
Coriolis Effect
• From the ball’s
perspective it makes
a straight line
• From the dot’s
perspective, it makes
a curve
Jupiter’s fasts rotation creates extreme
Coriolis Effect, stretching weather patterns
all the way around the planet
The Great Red Spot
• Been there as long as
astronomers have
looked at Jupiter
• 2-3x size of Earth
Similar Weather on Other Planets
Jovian Satellites
• 150+ known satellites of
Jovian planets
• Largest satellites were
likely formed with planets
– Smaller ones were likely
captured
• Largest satellites
resemble terrestrial
planets
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Spherical
Solid Surface
Geology
Hot interiors
Atmospheres
Magnetic fields
Galilean Satellites
Orbital Resonance
• When orbital
periods of two or
more bodies are
integer multiples
– Causes orbits to
be more elliptical
Io
• Most volcanically
active body in the
solar system
• Great eruption in
1996 photographed
by Galileo
– Plume extends 60
miles above surface
– Blue due to frozen
sulfur dioxide
Tidal Heating
• Tidal Friction is
caused by elliptical
orbit
– Stronger tides on one
side of orbit than other
– Cause by orbital
resonances
• Tidal Friction heats
up the body
Europa
• Surface covered in water ice
• Tidal stresses heat water, keep liquid layer
under the surface
• Very few craters, indicates geological activity
Titan
• Thick atmosphere
of 90% N,
Hydrocarbons
• Oceans of
methane
Rings
Saturn’s Rings
• Large gap called “Cassini division”
– Due to orbital resonance with satellite, Mimas
• Made up of tons of tiny particles of mostly ice
Gaps
• Rings caused by
particles being
bunched up into
similar orbital
distances
• Gaps caused by:
– Small “gap moons”
– Orbital resonances
with larger satellites
Cause of Rings
• All Jovian planets have rings
• Not remnants of ancient
formation material
– That material would not last
billions of years
• Must be constantly resupplied
– Constant collisions of small
satellites
– Get broken down into smaller
and smaller pieces