Planetary Heat Flow measurements and thermal disturbances caused by lander shadowing

Abstract

<p>The planetary heat flow is one of the fundamental quantities describing the thermal state of a planet. It influences the tectonic and volcanic processes we see at the surface and is closely connected to the planet’s geodynamic activity. It largely determines subsurface temperatures and provides one of the few constraints we have for thermal evolution models [1][2].</p><p> Upcoming lander missions will conduct in situ geophysical experiments and measure the planetary heat flow of Mars. The first such measurement is scheduled for ESA’s ExoMars mission, which will deliver a geophysical instrument package to the martian surface. This will include the Heat Flow and Physical Properties Package (HP³) [3], a heat flowprobe which will access the martian subsurface to a depth of 5 m and perform measurements of the soils thermophysical parameters and temperatures as a function of depth.</p><p> Here we will investigate how soil shadowing by the lander structure influences the subsurface soil temperatures and derive requirements of how meaningful measurements of the subsurface thermal gradient can be performed. Particular attention will be paid to the differences between short and long term measurements and measurements underneath and outside the lander structure.</p> [1] Breuer, D., and Spohn, T. (2003), J. Geophys. Res., 108, 81.<br /> [2] Hauck II, S.A., and Phillips, R.J. (2002), J. Geophys. Res., 107, 61.<br /> [3] Spohn, T., et al. (2001), Planet. Space Sci., 49, 1415, 15711577.<br />