Best known for his pioneering work in elucidating the mechanics of impacts and in the discovery of Earth-crossing bodies, Gene gained worldwide fame in March 1993 for his discovery, with Carolyn and colleague David Levy, of a comet that would strike Jupiter 16 months later. They are also credited with discovering more than 800 asteroids. But the one research interest he never tired of was Meteor Crater, the kilometer-wide pit east of Flagstaff, Arizona. While still in his teens, Gene realized that someday astronauts would walk on the Moon, and from that point forward his whole professional life would be directed toward becoming one of them. But a medical condition prevented him from ever being selected for the Apollo program.
Paleolake levels provide estimates of drainage basin water balance.
Archaeological evidence establishes spatial and temporal patterns of agricultural field use and abandonment. Prior to 1500 B.C., aridity in the altiplano precluded intensive agriculture. During a wetter period from 1500 B.C. to A.D. 1100, the Tiwanaku civilization and its immediate predecessors developed specialized agricultural methods that stimulated population growth and sustained large human settlements.