THE SHAPE OF THINGS IN THE SOLAR SYSTEM: THE MYRIAD CONTRIBUTIONS OF MARIA ZUBER TO PLANETARY GEOLOGY

More than any other individual in planetary science, Maria Zuber has pioneered the measurement and interpretation of the shapes of the surfaces of the inner planets, asteroids, and satellites and what those shapes mean for internal structure and dynamics, thermal and magmatic history, and surface-atmosphere interactions. She led the data reduction and analysis efforts for the laser ranging experiment on Clementine, which changed our understanding of the extent of isostatic compensation early in lunar history and elucidated for the first time the strongly aspherical pattern of early lunar mantle temperature and melt production. As Deputy Principal Investigator for the Mars Orbital Laser Altimeter instrument on Mars Global Surveyor, she co-led the acquisition of a superb topographic map of Mars, which has stimulated a new understanding of all phenomena that affect the Martian surface, from cratering and deformation, to volcanism and atmospheric circulation, to the erosional and depositional action of water and ice. She led the Laser Rangefinder experiment on the Near Earth Asteroid Rendezvous Shoemaker mission, producing the first detailed three-dimensional view of the shape of an asteroid as well as the first precise estimate of mean asteroid density. With students and colleagues she developed the idea that many tectonic features on the planets arise from instabilities in the lithosphere induced by in-plane or basal shear stress and that the mechanical properties of the lithosphere may be inferred from the characteristics (particularly the wavelengths) of these instabilities. Among her other current activities, she serves as team leader for the radio science gravity investigation on the Mars Reconnaissance Orbiter, Deputy Principal Investigator for the Lunar Orbiter Laser Altimeter on the Lunar Reconnaissance Orbiter, and chair of the Geophysics Discipline Group for the MESSENGER mission to Mercury, pointing to the strong likelihood that her research in the next few years will fully match in impact and importance the work for which she has deservedly earned the Planetary Geology Division's 2007 Grove Karl Gilbert Award.