The Study of Titan's Surface using Impact Craters and Analogues
Abstract
Titan, Saturn’s largest moon, is an icy world harbouring a subsurface water ocean, a substantial atmosphere, and a flowing liquid on its surface. These distinctive characteristics give rise to complex chemical reactions on Titan, and also render it akin to Earth in terms of its landforms and processes. This positions Titan as a key target for studying prebiotic chemistry. NASA's fourth New Frontiers mission, Dragonfly, is poised to explore Titan’s surface in the 2030s. Dragonfly’s primary study site will be Selk crater, a relatively fresh impact crater located in Titan’s equatorial sand seas. Impact craters serve as valuable markers for comprehending how geological processes shape and modify Titan’s surface. The central theme of this thesis revolves around investigating the impact cratering process on Titan, using remote sensing and numerical modeling techniques. Specifically, we seek to use the morphology and morphometry of Titan’s impact craters to constrain the amount of erosion that has occurred there. Given Titan's similarities to Earth, we study terrestrial craters in radar images as analogues to constrain the crater population on Titan, and hence, its surface age. Furthermore, we explore the extent of erosion that may have occurred at Titan’s craters by simulating the formation of fresh craters on Titan. These simulations investigate the influence of the thermal properties of methane clathrates on crater depths. These studies collectively contribute to a more nuanced understanding of the impact cratering process on Titan. The Dragonfly mission, in its exploration of Selk crater, will provide further insights into Titan’s geological history and subsurface structure, refining the surface age and erosion constraints presented in this work. To support future operations in Selk crater, we conducted an analogue mission simulation using an Unoccupied Aircraft System and applied lessons learned to the currently planned strategies for Dragonfly.