Jupiter’s inhomogeneous envelope

¹ SRON Netherlands Institute for Space Research, Niels Bohrweg 4, 2333 CA Leiden, The Netherlands
e-mail: ymiguel@strw.leidenuniv.nl
² Leiden Observatory, University of Leiden, Niels Bohrweg 2, 2333 CA Leiden, The Netherlands
³ Heidelberg Institute for Theoretical Studies (HITS gGmbH), Schloss-Wolfsbrunnenweg 35, 69118 Heidelberg, Germany
⁴ CITIES, NYUAD Institute, New York University Abu Dhabi, PO Box 129188, Abu Dhabi, UAE
⁵ Université Côte d'Azur, OCA, Lagrange CNRS, 06304 Nice, France
⁶ Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot 76100, Israel
⁷ Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721, USA
⁸ Department of Earth and Planetary Science, University of California, Berkeley, CA 94720, USA
⁹ Institute for Computational Science, University of Zurich, Winterthurerstr. 190, 8057 Zurich, Switzerland
¹⁰ University of Michigan, Climate and Space Sciences and Engineering, Ann Arbor, MI 48109, USA
¹¹ Space Research Corporation, Annapolis, MD 21403, USA
¹² NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
¹³ Department of Mechanical and Aerospace Engineering, Sapienza University of Rome, Italy
¹⁴ Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA, USA
¹⁵ Department of Astronomy, Cornell University, 122 Sciences Drive, Ithaca, NY 14853, USA
¹⁶ Carl Sagan Institute, Cornell University, 122 Sciences Drive, Ithaca, NY 14853, USA
¹⁷ Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125 USA
¹⁸ Southwest Research Institute, San Antonio, TX 78238, USA

Received: 27 January 2022
Accepted: 2 March 2022

Abstract

Context. 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-element distribution in Jupiter’s envelope.

Aims. 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.

Methods. 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.

Results. Our results show that the gravity constraints lead to a deep entropy of Jupiter corresponding to a 1 bar temperature that is 515 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 M_Earth, independently of the structure model (with or without a dilute core) and the equation of state considered. Furthermore, we robustly demonstrate that Jupiter’s envelope is inhomogeneous, 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.