Citation | Distinguished for theoretical studies of planetary interiors, Stevenson provided the first thermodynamic treatment of mixtures of hydrogen and helium under extremely high pressure, contributing to the understanding of the evolution of the interiors of the major planets. Also from the physics of condensed matter he has discussed tidal dissipation in the giant planets. He has contributed to the cosmochemistry of the outer solar system and the solar nebula and to the boundary between astrophysics and planetary physics by his own study of brown dwarf stars. He has applied the physics of the liquid state to elucidate the nature of the Earth's core. He has provided the first adequate theory of the absence of a magnetic field in Venus by showing that the energy source now supposed to drive convection in the Earth's core, i.e. from the freezing of the inner body, is not present in Venus because of the difference in phase diagrams in the two planets. He is investigating new ideas concerning the generation of the magnetic field of Mercury. He has brought an original and ingenious mind and a deep knowledge of physics to the task - yet in its early stages - of understanding the wealth of new data resulting from space exploration of the solar system. |