John S. Lewis is a professor emeritus of planetary science at the University of Arizona’s Lunar and Planetary Laboratory and is Chief Scientist at Deep Space Industries. His interests in the chemistry and formation of the solar system and the economic development of space have made him a leading proponent of turning potentially hazardous near-Earth objects into lucrative space resources. Prior to joining the University of Arizona, Lewis taught space sciences and cosmochemistry at the Massachusetts Institute of Technology. He received his education at Princeton University, Dartmouth College and the University of California, San Diego, where he studied under Nobel Laureate Harold Urey. An expert on the composition and chemistry of asteroids and comets, Lewis has written such popular science books as "Mining the Sky", "Rain of Iron and Ice", and "Worlds without End".