Devolatilization during rocky planet formation: Bridging theories and observations

Devolatilization — depletion of volatile elements (e.g., C, O, N, S, Na and K) in rocky planets relative to their host stars — is a common feature that has been observed in both the Solar System and exoplanet systems. Competing mechanisms have been proposed to explain this common feature, ranging from incomplete condensation of dust materials from an ultra-hot nebula with a host stellar composition, partial evaporation of planetesimals by short-lived radiogenic heating and/or collisional kinetic energy, as well as thermal processing of primordial pebbles in evolving protoplanetary disks and through accretion process. The compositional outcome of prevalent theories will be simulated and then tested against a wide range of empirical/observational data with the solar system rocky bodies and exoplanetary rocky materials as inferred from both ‘polluted’ white dwarfs and co-natal pairs of planet-hosting stars. It is anticipated to bridge theories and observations to understand in depth this potentially universal phenomenon of devolatilization in rocky planet formation – a pillar underpinning the chemical foundations of rocky worlds.