MOUNTAINS ON TITAN: OBSERVATION AND ANALYSIS FROM CASSINI RADAR

The Cassini RADAR Synthetic Aperture Radar (SAR) has revealed many remarkably Earth-like processes that have shaped the surface of Titan. Among the many diverse terrains on Titan’s surface, there are features that are radar bright in texture as seen by Cassini SAR of relatively high topography that we refer to as mountains. One of the great questions about Titan’s surface is: what is the origin of mountains, and are they a sign of internal geologic activity?

Titan’s mountainous features have been interpreted to have several origins under the broad hypotheses of endogenic (formed by internal energy) and exogenic (formed by external forces). Mountain ranges and ridges on Titan are hypothesized to have formed by contractional tectonism - thickening of the icy crust of Titan (Radebaugh et al. 2007; Mitri et al. 2010). However, Moore et al. (2010) argued a different hypothesis for mountains: an exogenic origin implying formation by external forces, such as impact cratering followed by erosion. Thus, in order to better understand the tectonic and erosional contributions to shaping Titan’s mountains, we analyze Cassini SAR images of mountainous terrains to: (1) determine the individual heights and slopes of mountain chains around Titan, and (2) analyze mountain distribution with height.

Our preliminary results on studies of mountain heights reveal summit peaks with a maximum slope of 37 degrees and maximum height of 3310 m. In this initial analysis, mountains of varying heights are located across Titan, although most of the maximum highest mountain peaks we measured so far are closer to the equator. Given mountains formed by contractional tectonism should lead to high features, our preliminary results favor the endogenic origin hypothesis. Studies of the distributions of these features with height will illuminate our understanding of the formation and erosional evolution of the mountains on Titan.