Saturn - Dressed to the Nines

Key Points

Size

• diameter 9 x > Earth (~120,000 km vs ~14,000 km)

• mass 95 x > Earth

Distance from Sun

http://www.ulink.net/stargazerdan/star.html

• 9.5x further than Earth

Revolution

• ~29 years

• 10.5 hours
• bulges at equator, flatted on top
• 10% slower at high latitudes

• ~92% H₂, ~7.5% He, ~.2%CH₄
• rem Jupiter ~86%H₂, 15% He
• Because of this composition Saturn would float
• Has belts and zones (like Jupiter) but they are not as noticeable

 The Rings

• inside this gravity (tidal forces) pulls things apart - the force of gravity is higher between the larger body than between the individual particles
  
• It's ~2.5x the radius of the larger body - so the rings are most likely to be a satellite that failed to accrete
• Does the Sun have a Roche Limit?

Ring rotation is measured by doppler shift

Composition is most likely water ice

Major Ring Divisions A, B, C as seen from Earth

http://www.arksky.org/saturn_stellar_occn.htm

A is outside ring it is separated from the B ring (brightest) by a space

Cassini's division

http://saturn.jpl.nasa.gov/index.cfm

shepherd moons

(NASA)

100s of thousands of rings w/ a constantly changing structure

(NASA)

Spokes

• particles about the rings possibly head in place by electrostatic forces
• occultation of a star shows that the spokes are about10-6 m. in size (dust particles in sunlight)
• another victory for non-optical sensing (50x better resolution)
  

Pioneer (1979) vs Voyager 1(1980) 100x data transmission capabilities

Satellites

30?

Mimas

Impact crater

Titan - THE BIG ONE!?

• thick atm.(1.5x Earth) mostly methane (organic)
• remove atm. just smaller than Ganymede, but bigger than Mercury,
• so it lost its position of biggest satellite (residents are happy as it cuts down on the number of tourists who come for the view)

http://saturn.jpl.nasa.gov/museums/index.cfm