Abstract DGP2026-118

Over the past half century humanity has made considerable progress exploring the rocky bodies of the solar system. Despite the inherent differences in the size, composition and history of each body, Mercury, Mars, and Luna all have similar unexplained surface characteristics. Resurfacing is dominated by plains volcanism of specific regions, strain related structures are predominantly contractional and their timing fits poorly with the thermal models currently established, and topography and gravity anomalies are preserved far out of isostatic equilibrium on the surface until present. None of these observations are particularly consistent with a rapid transition to stagnant lid following the magma ocean phase. 

An initial cooling period following the magma ocean, via heat-piping through the lithosphere could help reconcile these observations with theory. During this relatively short geological period of heat-piping, rapid resurfacing would occur similar to Jupiter’s moon Io, which would generate a thick, cold, mechanically stable crust able to preserve ancient hypsometry (i.e., Martian dichotomy) and equilibrium shape (i.e. Lunar fossil bulge). The period following heat pipe when the planet can no longer cool by advective processes (volcanism) so must cool by conductive processes (radiation) would mean the crust would warm and asymmetrically accumulate strain potentially explaining anti-correlation of faulting and age of surface observed on Mercury and Mars.

We propose that Heat-pipe cooling often follows the magma ocean phase on rocky planets, and represents the last global scale geodynamic activity of these bodies, explaining their matching surface characteristics, and preservation of geoidal disequilibrium to today.