Jupiter’s Evolution with Primordial Composition Gradients

Recent formation models of Jupiter suggest that it
could form with composition gradients. This
possibility directly affects our understanding of
Jupiter’s bulk composition and origin.
We present Jupiter’s evolution with a primordial
structure consisting of a composition gradient
with 40 M⊕ of heavy elements throughout the planet.
We show that for this primordial structure most of
the mixing occurs in the outer part of the gradient
during the early evolution (several 107 yr), leading to
an adiabatic outer envelope (60% of Jupiter’s
mass). We find that in that case the composition
gradient in the deep interior persists; suggesting
that ∼ 40% of Jupiter’s mass can be non-adiabatic
(and therefore, not fully-convective) with higher
temperatures than the ones derived from adiabatic
interiors.
The derived current-state structure can be viewed as
Jupiter with a diluted core, as suggested by recent
Jupiter structure models that fit Juno’s gravity data.