High-Resolution Thermal Environment of Recurring Slope Lineae in Palikir Crater, Mars, and Its Implications for Volatiles

Abstract

A thermophysical model for rough terrain is developed that is capable of processing spatial domains of megapixel size. This computational advance makes it possible to characterize thermal environments on Mars at unprecedented scale and at a resolution of 1 m per pixel. The model is applied to Palikir Crater, Mars, where many recurring slope lineae (RSL) are located, often in bedrock alcoves. In areas with RSL, subsurface water ice is not stable, that is, any subsurface ice is lost to the atmosphere in the long term. On large portions of the craters walls, water frost accumulates continuously for up to hundreds of sols each Mars year, but no relation is found between the location of RSL and seasonal water frost accumulation. Some RSL do not have access to even 1 m2 of water frost, at any time of the year. Where water frost is present, it stops accumulating in early southern spring at the latest, long before major RSL activity. Based on the model results, neither CO2 frost, perennial subsurface ice, nor seasonal water frost patches (>1 m2) are connected with RSL activity.