Volatiles Release from Metal-Silicate Interactions in Magma Oceans During Planetary Accretion

During planetary accretion, impacts vary in mass, velocity, and angle, producing magma oceans of different sizes and temperatures. Large impactors, more common in the late accretionary stages, contain iron cores that can emulsify into extremely small drops, which then rain down into the rocky planetary core. During its descent, metal and silicate chemically react, stripping the mantle of siderophile (iron-loving) elements and leaving lithophile (rock-loving) elements behind. To estimate the fraction of volatiles remaining in the magna ocean vs. the one stored into the core is essential to model the properties of the atmosphere of newly formed rocky planets. Further, the composition of the atmosphere influences the cooling rate of the magma ocean itself. A single simulation that can quantify this entire dynamics is presently beyond existing techniques. Using a newly developed fluid-dynamic numerical approach, based on the Lattice Boltzmann Method for fluid-dynamics, and Rothman-Keller approach for multiphase flow, we model the fate of the metal-silicate fluid dynamics in response to a wide range of realistic magma ocean scenario, considering impactors falling a different angles, iron continent, speed. Our approach tracks the descent of diapirs, each representing a coherent cloud of iron drops, through an entire magma ocean, identifying the descent environment (Pressure and Temperature vs depth, collective speed, volume of the magma ocean entrained into the cloud of diapirs).