HR: 11:20h
AN: U12A-02 INVITED     [Abstracts]
TI: Titan: Explorations of a Frontier with Terrestrial Allusions
AU: * Griffith, C A
EM: griffith@lpl.arizona.edu
AF: University of Arizona, Department of Planetary Sciences 1629 E. University Blvd., Tucson, AZ 85721 United States
AB: Saturn's largest moon, Titan, distinguishes itself from other moons by sporting an atmosphere with ten times the column abundance of Earth's. The moon's atmosphere is also similar to Earth's atmosphere in that it is nitrogen-based, rich in hydrocarbons, and hypothesized have a liquid cycle like the hydrological cycle, with clouds, rain and seas. (However, on Titan methane plays the role of terrestrial water.) Recent ground-based and Cassini observations indicate that large methane cloud systems concentrate at Titan's south pole. Radar images of Titan's surface suggest the presence of surface liquids, and near-IR measurements suggest that Titan's icy bedrock is exposed, despite the expected kilometer of organic photochemically-produced sediments. Nonetheless, at the time of writing this abstract little is known about Titan's lower atmosphere and surface, which are obscured by the thick veil of Titan's stratospheric haze. For example, we do not know the methane humidity of the atmosphere, or the surface composition, Nor do we understand the origin and evolution of the atmosphere, or the formation of clouds in an atmosphere with a radiative time constant that exceeds a Titan year by a factor of several. This year Cassini has begun to unveil Titan; it is equipped with an orbiter which began its close flybys of Titan on October 26, 2004, and with a probe which will descend into Titan's atmosphere on January 14 next year. Here I will provide a background to our understanding of Titan's atmosphere and surface, and underscore key open questions in the field. Frequent comparisons will be made between the structures of Titan's and Earth's lower atmospheres.
DE: 5400 PLANETOLOGY: SOLID SURFACE PLANETS
DE: 6062 Satellites
DE: 3300 METEOROLOGY AND ATMOSPHERIC DYNAMICS
DE: 0300 ATMOSPHERIC COMPOSITION AND STRUCTURE
DE: 0933 Remote sensing
SC: Union [U]
MN: 2004 AGU Fall Meeting