HR: 14:10h
AN: U23A-03 INVITED     [Abstracts]
TI: The First Year of Cassini RADAR Observations of Titan
AU: Elachi, C
EM: charles.elachi@jpl.nasa.gov
AF: Jet Propulsion Laboratory, California Institute of Technology, 4800 Oak Grove Dr, Pasadena, CA 91109 United States
AU: * Lorenz, R D
EM: rlorenz@lpl.arizona.edu
AF: Lunar and Planetary Lab, University of Arizona, 1629 E. University Blvd, Tucson, AZ 85721 United States
AB: Titan`s atmosphere is essentially transparent to Radar, making it an ideal technique to study Titan`s surface. Cassini`s Titan Radar Mapper operates as a passive radiometer, scatterometer, altimeter, and synthetic aperture radar (SAR). Here we review data from four fly-bys in the first year of Cassini`s tour (Ta: October 2004, T3: February 2005, T7: September 2005, and T8: October 2005.) Early SAR images from Ta and T3 (showing < 3% of Titan`s surface) reveal that Titan is geologically young and complex (see Elachi et al., 2005, Science 13, 970-4). Significant variations were seen between the range of features seen in the Ta swath (centered at ~50N, 80W) and T3 (~ 30N, 70W) : the large-scale radiometric properties also differed, with T3 being radar-brighter. A variety of features have been identified in SAR, including two large impact craters, cryovolcanic flows and a probable volcanic dome. Dendritic and braided radar-bright sinuous channels, some 180km long, are evidence of fluvial activity. `Cat scratches`, arrays of linear dark features seem most likely to be Aeolian. Radar provides unique topographic information on Titan`s landscape e.g. the depth of the 80km crater observed in T3 can be geometrically determined to be around 1300m deep. Despite the shallow large-scale slopes indicated in altimetry to date, many small hills are seen in T3. Scatterometry and radiometry maps provide large-scale classification of surface types and polarization and incidence angle coverage being assembled will constrain dielectric and scattering properties of the surface. Judging from the TA/T3 diversity, we expect further variations in the types and distribution of surface materials and geologic features in T7, which spans a wide range of Southern latitudes. T8 SAR will cover a near-equatorial dark region, including the landing site of the Huygens probe.
DE: 5415 Erosion and weathering
DE: 5420 Impact phenomena, cratering (6022, 8136)
DE: 5464 Remote sensing
DE: 5480 Volcanism (6063, 8148, 8450)
DE: 6281 Titan
SC: Union [U]
MN: Fall Meeting 2005