A MASSIVE CORE IN JUPITER PREDICTED FROM FIRST-PRINCIPLES SIMULATIONS

Hydrogen-helium mixtures at conditions of Jupiter's interior are studied with first-principles computer simulations. The resulting equation of state (EOS) implies that Jupiter possesses a central core of 14-18 Earth masses of heavier elements, a result that supports core accretion as the standard model for the formation of hydrogen-rich giant planets. Our nominal model has about 4 Earth masses of planetary ices in the H-He-rich mantle, a result that is, within a modeling uncertainty of 6 Earth masses, consistent with abundances measured by the 1995 Galileo entry probe mission, suggesting that the composition found by the probe may be representative of the entire planet. Interior models derived from this first-principles EOS do not give a match to Jupiter's gravity moment J(4) unless one invokes interior differential rotation, implying that Jovian interior dynamics has an observable effect on the high-order gravity field.