Titan

21 October 2011

Titan [2003]• Second-largest moon in SS

• Density ~1900 kg/m3

• thick atmosphere! Sublimation

• N2 (90%), methane, ethane

• ethane may condense• clouds,

rain,oceans/lakes/ponds/erosion???

• Geology unknown due to thick atmosphere

Voyager 1981

Titan [2005]

• Thick Atmosphere

• N2 (90%), methane, ethane

• methane clouds, rain, lakes

• Geology • Erosion!!!!!!!!!!• Volcanism, Tectonics

• A few impact craters

Huygens

Landing Site

Rounded cobblesresemble Mars

Titan’s LakesOf methane mostly(& ethane)

Few 100m deep

Red areas are those that changed between images a year apart

Blue appeared 2004-5

solid vs. liquidFalse Color - Radar Reflectivity

Cassini Radar images

Lakes- high latitudes

440 km impact crater Minerva

Braided channels – floods?

Linear dunes near equator

Geology

25 km

440 km diameter

Impact Crater

Dune Field

Cryovolcanic Extrusion ?

• Cryovolcanism • Impact cratering• Dune field formation

Atmospheric pressure at surface ~1.5 bars

Upper haze layersPhotochemical smog

Temps ~80-90K= -300 F

Surface Surface Chemistry andChemistry andinteraction with interaction with the atmospherethe atmosphere

Ices + Liquids + Ices + Liquids + Aerosol Aerosol PrecipitatesPrecipitates

Methane rain

Titan has a "hydrological cycle" like Earth but with methane instead of water!