Jupiter Radius Mass Surf. Gravity Density Semi-major axis Orbital Period Rotation Period 142,984 km 1.90 x 10 27 kg 23.1 m/s 2 1.33 g /cm 3 778.6 x 10 6 km 11.86 years 9.925 hrs Largest of all the planets (size & mass) Hosts ~ 60 moons, most of which are captured asteroids
Structure Composition: 90% H 2, 10% He, 0.2% CH 4, 0.02% NH 3 Upper Atmosphere (1000 km) Band appearance caused by high speed winds (640 km/hr) & differential rotation
Belts & Zones
Great Red Spot High pressure storm in S. Hemisphere D = 25,000 km 8 km above upper atmosphere 6 day rotation period 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
Magnetic Field Metallic hydrogen is highly conductive to electricity; coupled with FAST rotation! source of Jupiter s strong magnetic field Aurora Io Torus
Ring System Found by Voyager 1 in 1979 Low reflectivity = dust grains 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.
Comet Shoemaker-Levy 9 Only comet impact of another planet ever observed (July 1994) K fragment impact T ~ 7500 K
Galilean Moons Io - most volcanically active object in S.S. Surface regularly renewed by lava flows
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.
Galilean Moons Europa surface is highly reflective and very smooth - Subsurface ocean Surface cracks from H 2 O volcanoes Very thin oxygen atmosphere?
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?
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 CO 2 atmosphere Gipul Catena crater chain
Saturn Radius Mass Surf. Gravity Density Semi-major axis Orbital Period Rotation Period 120,536 km 5.69 x 10 27 kg 9.02 m/s 2 0.69 g /cm 3 1.43 x 10 9 km 29.46 years 10.66 hours Similar to Jupiter in terms of: Composition Belt/zone circulation Interior
Ring System 1 st observed by Galileo in 1610 as protrusions which vanished by 1612 Viewing angle changes
Ring System Composed of dust/ice particles (1 cm 1 m) Cassini Division D = 265,000 km Thickness = 2 km (transparent)
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
Shepherd Satellites Moons that keep material confined to the rings. Prometheus F ring
Ring Effects Ring Spokes charged dust trapped in Saturn s magnetic field Gravitational influence of Pan
Ring Effects Prometheus Braided F Ring
Largest moon of Saturn Titan CH 4 haze Surface Possible source of organic molecules (life?) and fuel Cassini mission sent Huygens probe to surface: January 5, 2005
Uranus Neptune 51,118 km 8.66 x 10 25 kg 9.60 m/s 2 1.27 g /cm 3 2.87 x 10 9 km 84.1 years 17.24 hours Radius Mass Surf. Gravity Density Semi-major axis Orbital Period Rotation Period 49,528 km 1.02 x 10 26 kg 11.0 m/s 2 1.64 g /cm 3 4.50 x 10 9 km 164.8 years 16.11 hours
Uranus Neptune Excess methane causes blue appearance Magnetic fields are greatly tilted and off-center
Uranus 1 st planet discovered not known to ancients found by William Herschel during stellar parallax studies (1781) plotted as a star over 20 times
Rotational axis is tilted 97.3 Uranus Atmosphere circulates heat to keep temperature uniform
Uranus Rings: 1 st observed during a 1977 occultation As Uranus passes in front the star, the star s brightness will drop
Neptune 1 st 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
Pluto Charon Pluto Radius: Mass: Surf. Gravity: Density: Semi-major axis Orbital Period Rotation Period 1,195 km 1.19 x 10 22 kg 0.59 m/s 2 1.75 g /cm 3 5.87 x 10 9 km 247.7 years 6.39 days i orb 17.1º Eccentricity 0.244
New Moons?
Pluto Percival Lowell predicted planet w/ M = 7 M Earth 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
Pluto Searched star fields for ~ 1 year; discovered February 18, 1930 Comes closer than Neptune Tidally locked Charon Only ~ twice the size of Charon Comet-like In Kuiper Belt Found serendipitously