“…For such a cloud, however, having heavy element abundance Z = Z®, the total mass of rock and ice condensate within the gas rings shed at the orbits of J, S, U, and N are 9.5, 7.1, 5.2, and 3.8 M®, respectively. If the condensate in each ring were to aggregate into a single planetary core, the masses of the cores would fall short of the values measured by Pioneer 11 (Hubbard et al 1980), or deduced from planetary interior models (Hubbard and MacFarlane 1980), by factors of 2.1, 2.6, 2.5, and 4.2, respectively. The same problem occurs in the Galilean system of satellites, where eqn.…”