The nature of gas giant planets

TL;DR

This paper reviews recent advances in understanding the complex internal structures of gas giant planets like Jupiter and Saturn, highlighting their unique features and implications for exoplanet studies.

Contribution

It summarizes new modeling methods and recent findings that reveal inhomogeneous, non-convective, and fuzzy core structures in gas giants.

Findings

Jupiter and Saturn have complex, inhomogeneous interiors.

Significant differences exist between Jupiter and Saturn.

These findings impact exoplanet characterization and planetary formation theories.

Abstract

Revealing the true nature of the gas giant planets in our Solar System is challenging. The masses of Jupiter and Saturn are about 318 and 95 Earth masses, respectively. While they mostly consist of hydrogen and helium, the total mass and distribution of the heavier elements, which reveal information on their origin, are still unknown. Recent accurate measurements of the gravitational fields of Jupiter and Saturn together with knowledge of the behavior of planetary materials at high pressures allow us to better constrain their interiors. Updated structure models of Jupiter and Saturn suggest that both planets have complex interiors that include composition inhomogeneities, non-convective regions, and fuzzy cores. In addition, it is clear that there are significant differences between Jupiter and Saturn and that each giant planet is unique. This has direct implications for giant exoplanet characterization and for our understanding of gaseous planets as a class of astronomical objects. In this review we summarize the methods used to model giant planet interiors and recent developments in giant planet structure models.