Gas giants are believed to form by the accretion of hydrogen-helium gas around an initial protocore of rock
and ice. The question of whether the rocky parts of the core dissolve into the fluid H-He layers following
formation has significant implications for planetary structure and evolution. Here we use ab initio calculations
to study rock solubility in fluid hydrogen, choosing MgO as a representative example of planetary
rocky materials, and find MgO to be highly soluble in H for temperatures in excess of approximately
10000 K, implying significant redistribution of rocky core material in Jupiter and larger exoplanets