Effects of Methane Clathrate on the Depth of Titan’s Craters

mpact craters, the results of one of the ubiquitous geologic processes in the Solar System, provide a natural tool by which planetary crusts can be examined. Titan’s surface, for example, exhibits craters that are substantially shallower than craters on similarly sized icy satellites, such as Jupiter’s moons, Ganymede and Callisto. Aeolian erosion and infilling might account for some of this, but it is also possible that Titan’s crater form unnaturally shallow.  In this project we explore the hypothesis, that methane clathrates on Titan influence the crater formation process. Methane clathrates have a lower thermal conductivity than water ice and can significantly affect the thermal profile of the crust. If a layer of clathrates forms at the surface, higher temperatures occur at shallower depths. Warm water ice at shallow depths may cause Titan’s craters to both form with shallower depths and experience enhanced viscous relaxation of topography. We will examine these questions by simulating impact formation and relaxation using both shock physics codes and finite element models.