Larry W. Esposito is Professor of Astrophysical and Planetary Sciences at the University of Colorado Boulder, and also the principal investigator of the Ultraviolet Imaging Spectrograph (UVIS) experiment on the Cassini space mission to Saturn. He was chair of the Voyager Rings Working Group, and, as a member of the Pioneer Saturn imaging team, he discovered Saturn's F ring. Dr Esposito has participated in numerous US, Russian and European space missions and used the Hubble Space Telescope for its first observations of the planet Venus. His awards received include the Harold C. Urey Prize from the American Astronomical Society, the NASA Medal for Exceptional Scientific Achievement, and the Richtmyer Lecture Award from the American Association of Physics Teachers and the American Physical Society. Dr Esposito has served as chair of the National Academy of Sciences Committee on Planetary and Lunar Exploration (COMPLEX), and is a Fellow of the American Geophysical Union.