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SaturnSaturn ! Saturn is the second largest planet in the Solar System.

! There are 30 known satellites of Saturn.

! The largest, Titan, has a thick nitrogen-rich atmosphere.

! Saturn has an extensive magnetosphere.

Saturn emits 79% more energy than it receives from the Sun.

What makes those colorful golden bands in Saturn’s upper atmosphere?

---Ammonia ice crystals

Saturn, Physical AttributesSaturn, Physical Attributes" Mean distance from Sun ≈ 9.5 AU" Radius ≈ 9.5 × REarth" Mass ≈ 95 × MEarth" Density = Mass÷Volume ≈ 0.7 gm/cm3.

" Lowest density of any planet." Density of water = 1.0 gm/cm3." Can float in water!

" Low density implies composition similar to Jupiter’s; predominantly hydrogen and helium

!Saturn’s primary atmospheric contents are:!Hydrogen (94%)!Helium (6%)

!In addition, there are traces of ammonia, methane, ethane, phosphine, acetylene,methylacetylene, and propane.

!Saturn has the second fastest measured winds in the Solar System.

!Only Neptune has faster winds.

Saturn, More Physical AttributesSaturn, More Physical Attributes

Saturn, Interior CompositionSaturn, Interior Composition

" Overall structure similar to Jupiter’s" Mantle of liquid molecular hydrogen" Lower mantle of metallic hydrogen" Much more oblate than Jupiter. Equatorial diameter 10% larger at

than polar" Rocky core is larger than Jupiter’s" 26% of Saturn’s mass is in its rocky core (24 times the Earth mass!)

!Dark Cassini Division between A and B rings;Encke Division separates F and A

!Icy particles from dust grain up to 10 m sizes

!All rings within the Roche Limit !Shepherd satellites

!Mimas produces CassiniDivision

Saturn, RingsThree main rings (A, B and C) from Earth;

Many more found by spacecraft

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Saturn, SatellitesSaturn, Satellites" Extensive satellite system - similar to Jupiter’s. 18

moons; most are small" Most interesting moon is Titan

" Nearly as big as Mercury" Has an atmosphere rich in nitrogen and, perhaps, seas

of the hydrocarbon ethane" Might have formed organic molecules (HCN, for one)

that are precursors of building blocks of life" To be explored by Cassini + Huygens in 2004

Cassini is a joint NASA/ESA project designed to accomplish an exploration of the Saturnian system with its CassiniSaturn Orbiter and Huygens Titan Probe.