# Jupiter's formation and its primordial internal structure

## TL;DR

This paper models Jupiter's formation to determine its primordial internal structure, revealing a convective outer envelope with compositional gradients and a potentially larger, mixed core, informing future internal models and Juno mission data interpretation.

## Contribution

It provides a detailed model of Jupiter's primordial heavy element distribution and core structure, considering compositional gradients and their effects on internal temperature and core mass.

## Key findings

- Outer envelope is convective and homogeneous
- Inner regions have compositional gradients
- Core mass can be up to 15 Earth masses, including hydrogen and helium

## Abstract

The composition of Jupiter and the primordial distribution of the heavy elements are determined by its formation history. As a result, in order to constrain the primordial internal structure of Jupiter the growth of the core and the deposition and settling of accreted planetesimals must be followed in detail. In this paper we determine the distribution of the heavy elements in proto-Jupiter and determine the mass and composition of the core. We find that while the outer envelope of proto-Jupiter is typically convective and has an homogeneous composition, the innermost regions have compositional gradients. In addition, the existence of heavy elements in the envelope leads to much higher internal temperatures (several times 10$^4$ K) than in the case of a hydrogen-helium envelope. The derived core mass depends on the actual definition of the core: if the core is defined as the region in which the heavy-element mass fraction is above some limit (say 0.5), then it can be much more massive ($\sim$ 15 M$_{\oplus}$) and more extended (10\% of the planet's radius) than in the case where the core is just the region with 100\% heavy elements. In the former case Jupiter's core also consists of hydrogen and helium. Our results should be taken into account when constructing internal structure models of Jupiter and when interpreting the upcoming data from the {\it Juno} (NASA) mission.