Download Jovian Planets

Jupiter
Radius
Mass
Surf. Gravity
Density
Semi-major axis
Orbital Period
Rotation Period
142,984 km
1.90 x 1027 kg
23.1 m/s2
1.33 g /cm3
778.6 x 106 km
11.86 years
9.925 hrs
Largest of all the planets (size & mass)
Hosts ~ 60 moons, most of which are captured asteroids
MPP©2004
Structure
Composition: 90% H2, 10% He, 0.2% CH4, 0.02% NH3
Upper Atmosphere (1000 km)
Band appearance caused by high speed
winds (640 km/hr) & differential rotation
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Belts & Zones
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Great Red Spot
High pressure storm in S. Hemisphere
D = 25,000 km
8 km above upper atmosphere
6 day rotation period
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Persisted for 400 years!
Interior
Pressure and Temperature increase at greater depths
Pressure gets so intense, the hydrogen forms a liquid-metallic state
Core is still expending energy left over from initial formation
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Magnetic Field
Metallic hydrogen is highly conductive to electricity; coupled with
FAST rotation ! source of Jupiter’s strong magnetic field
Aurora
Io Torus
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Ring System
Found by Voyager 1 in 1979
Low reflectivity = dust grains
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Within Jupiter’s Roche Limit
Roche Limit
Boundary around a massive planet where tidal forces become so
strong that any object (moon, asteroid, comet) will be torn apart.
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Comet Shoemaker-Levy 9
Only comet impact of another planet ever observed (July 1994)
K fragment impact
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T ~ 7500 K
Galilean Moons
Io - most volcanically active object in S.S.
Surface regularly renewed by lava flows
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Galilean Moons
Io’s volcanism is driven by tidal heating as it orbits Jupiter
Quick revolution (1.88 days) & slightly eccentric orbit creates tidal
forces that squeeze Io; keeps interior molten.
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Galilean Moons
Europa – surface is highly reflective and very smooth
- Subsurface ocean
Surface cracks from H2O volcanoes
Very thin oxygen atmosphere?
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Galilean Moons
Ganymede – largest satellite in the Solar System
Crust made of ice 500 km thick floating on slushy mantle
Evidence of past tectonic activity
Very thin oxygen atmosphere?
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Galilean Moons
Callisto – most heavily cratered object in the Solar System
• 200 km thick ice layer
• 10 km salt water ocean under crust
VERY thin CO2 atmosphere
Gipul Catena – crater chain
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Saturn
Radius
120,536 km
5.69 x 1027 kg
Mass
Surf. Gravity
Density
9.02 m/s2
0.69 g /cm3
Semi-major axis
1.43 x 109 km
Orbital Period
29.46 years
Rotation Period
10.66 hours
Similar to Jupiter in terms of:
• Composition
• Belt/zone circulation
• Interior
MPP©2004
Ring System
1st observed by Galileo in 1610 as “protrusions” which “vanished” by 1612
Viewing angle changes
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Ring System
Composed of dust/ice particles (1 cm – 1 m)
Cassini Division
D = 265,000 km
Thickness = 2 km (transparent)
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Ring System
Three main rings (A, B, C) composed of thousands of thinner rings
Cassini
Voyager 1
Gaps result from orbital resonance with Saturn’s moons
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Shepherd Satellites
Moons that keep material confined to the rings.
Prometheus
F ring
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Ring Effects
Ring Spokes – charged dust trapped
in Saturn’s magnetic field
Gravitational influence of Pan
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Ring Effects
Prometheus
Braided F Ring
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Titan
Largest moon of Saturn
CH4 haze
Surface
Possible source of organic molecules (life?) and fuel
Cassini mission sent Huygens probe to surface: January 5, 2005
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Uranus
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Neptune
51,118 km
Radius
49,528 km
8.66 x 1025 kg
Mass
1.02 x 1026 kg
9.60 m/s2
Surf. Gravity
11.0 m/s2
1.27 g /cm3
Density
1.64 g /cm3
2.87 x 109 km
Semi-major axis
4.50 x 109 km
84.1 years
Orbital Period
164.8 years
17.24 hours
Rotation Period
16.11 hours
Uranus
Neptune
Excess methane causes blue appearance
MPP©2004
Magnetic fields are greatly tilted and off-center
Uranus
• 1st planet discovered not known to ancients
• found by William Herschel during
stellar parallax studies (1781)
• plotted as a star over 20 times
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Uranus
Rotational axis is tilted 97.3°
Atmosphere circulates heat to keep temperature uniform
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Uranus
Rings: 1st observed during a 1977 occultation
As Uranus passes in front the star, the star’s brightness will drop
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Neptune
• 1st planet predicted to exist by theory (Adams & Leverrier)
• discovered by Johanne Galle (1846)
• plotted by Galileo on two occasions while observing Jupiter
Methane cirrus clouds
Great Dark Spot
Small Dark Spot
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Pluto
Radius:
Charon
Mass:
Surf. Gravity:
Pluto
Density:
Semi-major axis
Orbital Period
Rotation Period
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1,195 km
1.19 x 1022 kg
0.59 m/s2
1.75 g /cm3
5.87 x 109 km
247.7 years
6.39 days
iorb
17.1º
Eccentricity
0.244
New Moons?
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Pluto
Percival Lowell predicted planet w/ M = 7 MEarth was beyond Neptune
Searched for planet for 10 years, but to no avail
Lowell
Lowell Observatory
Flagstaff, AZ
Tombaugh, 1922
Clyde Tombaugh hired to look for predicted planet
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Pluto
Searched star fields for ~ 1 year; discovered February 18, 1930
• Comes closer than Neptune
• Tidally locked Charon
• Only ~ twice the size of Charon
MPP©2004
• Comet-like
• In Kuiper Belt
• Found serendipitously