Abstract Title: Comparative study of impact craters on Earth and Titan using radar images

Abstract Submitted to: PLANETARY SCIENCES

Abstract Text:

Titan, the largest moon of Saturn, is a prime candidate for future space exploration. It is the only planetary body in our solar system, besides Earth, that has liquid on its surface and a thick, nitrogen-rich atmosphere. The RADAR instrument on NASA’s Cassini spacecraft mapped the surface of Titan and detected a low number of impact craters compared to nearby Saturnian satellites. The low crater count is likely due to atmospheric shielding, and erosion and burial of craters. This is similar to the reduced number of craters seen on Earth, as a result of weathering and erosion, compared to the heavily cratered lunar surface. Erosion and burial are some of the main processes responsible for crater degradation on both surfaces, making Earth a strong analogue for studying Titan’s craters. There are 201 confirmed craters on Earth which have been identified through field and laboratory studies. Of these craters, 67 are buried and therefore unobservable from orbit. In addition, craters formed in marine environments (also present on Titan) lack the significant surface topography necessary to be recognized by orbital satellites. This study proposes to determine the percentage of exposed terrestrial craters that can be identified in synthetic aperture radar data, as an analogue for Titan. Radar data from two different sensor bands will be used, allowing for the investigation of crater roughness at centimeter to decimeter scales. Preliminary characterization of 40 terrestrial craters shows that ~50% are distinctly visible in radar images. A complete study will help us to infer the number of unobservable impact craters on Titan. An accurate crater population for Titan informs constraints on the age of its surface, a value which is critical for models of the formation and evolution of Titan. All of these factors help build a comprehensive history and understanding of Titan, one of the most astrobiologically significant planetary bodies in our solar system.