Shock Compression of Deuterium and the Interiors of Jupiter and Saturn

Recently, deuterium has been the focus of a high level of experimental andtheoretical activity that was sparked by a disagreement on the experimentalvalue of the maximum compression along the Hugoniot. The behavior of deuteriumat Mbar pressures is not well understood. It is of great interest to understand how the current uncertainty on thehydrogen/deuterium EOS affects the inferred structures of Jupiter and Saturn.In particular, the mass of a core of heavy elements (other than H and He) andthe total mass of those heavy elements in these two planets are quite sensitiveto the EOS of hydrogen and constitute important clues to their formationprocess. We present a study of the range of structures allowed for Jupiter andSaturn by the current uncertainty in the hydrogen EOS and astrophysicalobservations of the two planets. An improved experimental understanding ofhydrogen at Mbar pressures and better determinations of the gravitationalmoments of both planets are necessary to put tight bounds on their internalstructure.Comment: 35 pages, including 12 figures. To appear in the Astrophysical Journa