Abstract:
I show that many crucial assumptions used to describe the interior thermal and tectonic evolution of rocky planets (from Earth and Mars to super-Earths) are disagreeing with observational and experimental constraints. It can be shown that such assumptions, especially in relation to mantle rheology, rather mimic planets made of honey then of rock in certain cases.
Here, I present a novel approach uniting first principles, parameterized 1D models, and full 2D/3D mantle convection evolution models, which allows to correct such inconsistencies and to fundamentally revise our understanding of the tectonic and interior evolution of rocky planets. This new approach leads to plate tectonics being ideally initiated early on by the development of hot mantle plumes and boosted by a dry mantle and a late meteoritic delivery of oceans. For Venus, it leads to an unstable tectonic configuration where the high surface temperatures allow to initiate but not to maintain plate tectonics. And for the search for life in the Galaxy, it allows us to start creating maps that connect planet observables (e.g., planet mass, age, radius, structure, composition) to geodynamic activity.
This self-consistent evolutionary interior and tectonic framework also opens a door to systematically connect geodynamics to the evolution of metabolic pathways and the origins of life - by studying the time-dependent (and for Mars and Earth local) geodynamic production of hydrogen and complex hydrocarbons.