Prof. John S. Lewis has research interests in two distinct areas: applications of chemistry to planetary sciences, and space development. The former program includes modeling of chemical processes in the early Solar System, condensation-accretion models of the terrestrial planets and giant-planet satellite systems, the compositional relationships between meteorites, asteroids, comets, and planets, and the chemical evolution of planetary atmospheres and surfaces. His other interests center on the characterization and economic development of the material and energy resources of near-Earth space. His recent publications include three popular science books, Rain of Iron and Ice (on comet and asteroid bombardment of Earth; also in German translation), Mining the Sky (on space resources for use in space and on Earth; also in German and Chinese translation), and Worlds Without End (on the nature and distribution of planets in the universe from ancient writings on the plurality of worlds to the current flood of observations of planets in orbit about other stars), all from Helix Books. He also was technical editor of the University of Arizona Press technical volume Resources of Near-Earth Space and authored the recent book Comet and Asteroid Impacts: Quantitative Modeling of Hazards on a Populated Earth (Academic Press, 2000) as well as a revised edition of the upper-division undergraduate planetary science textbook Physics and Chemistry of the Solar System.