Author/Authors :
Stofan، نويسنده , , E.R. and Lunine، نويسنده , , J.I. and Lopes، نويسنده , , R. and Paganelli، نويسنده , , F. and Lorenz، نويسنده , , R.D. and Wood، نويسنده , , C.A. and Kirk، نويسنده , , R. and Wall، نويسنده , , S. and Elachi، نويسنده , , C. and Soderblom، نويسنده , , L.A. and Ostro، نويسنده , , Ulrich S. and Janssen، نويسنده , , M. and Radebaugh، نويسنده , , J. and Wye، نويسنده , , L. and Zebker، نويسنده , , H. and Anderson، نويسنده , , Y. and Allison، نويسنده , , M. and Boehmer، نويسنده , , Jonathan R. and Callahan، نويسنده , , P. and Encrenaz، نويسنده , , P. and Flamini، نويسنده , , E. and Francescetti، نويسنده , , G. and Gim، نويسنده , , Y. and Hamilton، نويسنده , , G. and Hensley، نويسنده , , S. and Johnson، نويسنده , , W.T.K. and Kelleher، نويسنده , , K. and Muhleman، نويسنده , , D. and Picardi، نويسنده , , G. and Posa، نويسنده , , F. and Roth، نويسنده , , L. and Seu، نويسنده , , R. and Shaffer، نويسنده , , S. and Stiles، نويسنده , , B. and Vetrella، نويسنده , , S. and West، نويسنده , , R.، نويسنده ,
Abstract :
The first two swaths collected by Cassiniʹs Titan Radar Mapper were obtained in October of 2004 (Ta) and February of 2005 (T3). The Ta swath provides evidence for cryovolcanic processes, the possible occurrence of fluvial channels and lakes, and some tectonic activity. The T3 swath has extensive areas of dunes and two large impact craters. We interpret the brightness variations in much of the swaths to result from roughness variations caused by fracturing and erosion of Titanʹs icy surface, with additional contributions from a combination of volume scattering and compositional variations. Despite the small amount of Titan mapped to date, the significant differences between the terrains of the two swaths suggest that Titan is geologically complex. The overall scarcity of impact craters provides evidence that the surface imaged to date is relatively young, with resurfacing by cryovolcanism, fluvial erosion, aeolian erosion, and likely atmospheric deposition of materials. Future radar swaths will help to further define the nature of and extent to which internal and external processes have shaped Titanʹs surface.
