Results from a Comparison of Approximate Analytical Solutions with a Detailed Numerical Inversion Analysis to Determine the Thermal Conductivity of the Regolith at the Mars InSight Landing Site Using Data from HP3 Heating Experiments

Abstract

A direct measurement of the regolith thermal conductivity at the Mars InSight landing site (4.50°, 132.62°E) was made by heating experiments using the physical properties package (HP3) of the Mars InSight mission. Temperature and time data from these heating experiments, after removal of background temperature variations, were analyzed using a finite element model for which Monte Carlo simulations were run varying regolith thermal conductivity, density, thermal contact conductance between the probe and the regolith to determine parameter combinations that best fit the heating curve. In terms of simulating details of heating experiment this data reduction and numerical inversion is as complete as possible within the current constraints of the experiment. However, no information was included in the model concerning regolith thermal conductivity variations radial to the probe caused during penetration of the probe.