We are pleased to announce a Petrology Lunch with Maggie Thompson and Paolo Sossi on the topic of: Volatile Partitioning Experiments and Models to Constrain the Rocky Planet Interior-Atmosphere Connection.

Abstract:

Due to significant heating during planet formation, it is likely that most rocky planets undergo a magma ocean phase where their surface is partially or completely molten. During this phase, the composition of a planet’s atmosphere overlaying the magma ocean will be modulated by solubilities of major gas species in the magma. The magma ocean stage is critical for setting the volatile inventory of a planet and therefore its habitability potential. At present, we lack a comprehensive understanding how volatile elements partition between the interior and atmosphere for diverse planetary melt compositions representative of the magma ocean stage on rocky planets. To fill this gap, we will present new H2O and H2 solubility experiments on planetary melt analog materials at high temperatures using an aerodynamic laser levitation furnace and a 1-bar H2-CO2 gas-mixing furnace (Sossi et al. 2023 EPSL, Thompson et al. 2025 in review). We will present the findings of our experiments and discuss how they can be incorporated into a new volatile partitioning code, Atmodeller, which computes chemical equilibrium at the surface-atmosphere interface of low-mass planets. Coupling laboratory experiments and numerical models is essential for understanding the interior-atmosphere connection for rocky planets, from the early Earth to rocky exoplanets orbiting nearby stars.