Material Properties of Saturn’s Interior from Ab Initio Simulations

Abstract

We investigate the material properties of a mixture of hydrogen, helium, and oxygen representative of Saturn’s interior at pressure–temperature conditions of a recent Saturn model (see Mankovich & Fortney) with molecular dynamics simulations based on density functional theory. Their model considers the demixing of hydrogen and helium and predicts a He-rich layer above a diluted core. We calculate the thermodynamic and transport properties and discuss the impact on Saturn’s evolution and interior structure. We find a significant impact of the He-rich layer on the specific heat capacity, speed of sound, viscosity, diffusion coefficients, thermal and electrical conductivity, Lorenz number, and magnetic and thermal diffusivities.