The enigma of Venusian coronae

Our neighbouring planet Venus holds key insights into terrestrial planet evolution. At present, there is no mosaic of mobile tectonic plates on the planet, yet Venus surface is littered with tectonic and/or volcanic structures. Many of these structures seem to be related to regional-scale tectonic deformation and/or mantle upwellings, but it remains questionable exactly when, and how, Venus is resurfacing. Unique to Venus are the so-called coronae, ~circular crown-like structures with traces of tectonic and volcanic activity. Coronae are perhaps the most profound surface manifestations of mantle plume upwellings and/or magmatism, and may be fundamental for understanding Venus interior dynamics through time. The exact processes underlying their development and the reasons for their diverse morphologies have been widely debated in the past, with several key outcomes for the Venus scientific community. Here, I present an overview of the models of the formation of coronae to date, and pay particular attention to the successes of formation models involving the interaction between a thermal mantle plume and the Venusian lithosphere. I discuss what insights these studies have given on the thermal evolution of Venus, as well as its present-day geological activity. Moreover, I present new results on the gravitational signatures of previously modelled corona structures[1], and discuss whether we can distinguish between different stages of corona evolution. These outcomes may be important for future radio science experiments aboard ESAs EnVision orbiter. Finally, Ill discuss several key directions for future research on these enigmatic coronae structures, which are relevant in light of the upcoming Decade(s) of Venus Science. While I will mainly showcase numerical and analogue modelling studies, I invite scientists from all disciplines of the Geo- and Planetary sciences to join the discussion on how these unique coronae can provide key information on the evolution of the interior and surface of Earths twin planet.[1] Gulcher, A.J.P., Gerya, T.V., Montesi, L.G.J., and Munch, J., (2020). Corona structures driven by plumelithosphere interactions and evidence for ongoing plume activity on Venus. Nature Geoscience, 13, 547554.