Jupiter's inhomogeneous envelope

TL;DR

This study uses comprehensive interior models and Bayesian analysis to reveal that Jupiter's envelope is inhomogeneous with a heavy-element enrichment, providing new insights into its formation and internal structure.

Contribution

It introduces a Bayesian approach to interior modeling that constrains Jupiter's heavy-element distribution and demonstrates envelope inhomogeneity with implications for planetary formation.

Findings

Jupiter's gravity suggests a higher deep entropy and temperature.

Uncertainties in the equation of state significantly affect heavy-element estimates.

Jupiter's envelope is inhomogeneous, with more heavy elements inside than outside.

Abstract

While Jupiter's massive gas envelope consists mainly of hydrogen and helium, the key to understanding Jupiter's formation and evolution lies in the distribution of the remaining (heavy) elements. Before the Juno mission, the lack of high-precision gravity harmonics precluded the use of statistical analyses in a robust determination of the heavy-elements distribution in Jupiter's envelope. In this paper, we assemble the most comprehensive and diverse collection of Jupiter interior models to date and use it to study the distribution of heavy elements in the planet's envelope. We apply a Bayesian statistical approach to our interior model calculations, reproducing the Juno gravitational and atmospheric measurements and constraints from the deep zonal flows. Our results show that the gravity constraints lead to a deep entropy of Jupiter corresponding to a 1 bar temperature 5-15 K higher than traditionally assumed. We also find that uncertainties in the equation of state are crucial when determining the amount of heavy elements in Jupiter's interior. Our models put an upper limit to the inner compact core of Jupiter of 7 Earth masses, independently on the structure model (with or without dilute core) and the equation of state considered. Furthermore, we robustly demonstrate that Jupiter's envelope is inhomogenous, with a heavy-element enrichment in the interior relative to the outer envelope. This implies that heavy element enrichment continued through the gas accretion phase, with important implications for the formation of giant planets in our solar system and beyond.