Eugene Shoemaker, a geologist who shaped his science into a new form, astrogeology, and propelled it to the forefront in lunar and planetary exploration, was probably the 20th century's leading planetary scientist. Born in Los Angeles, Gene Shoemaker hurried through high school and the California Institute of Technology, and joined the U.S. Geological Survey (USGS) in 1948 at the early age of 20. He quickly realized that the United States was going to explore the Moon and, since the Moon must be made of rock that obeyed geological laws, it should be explored by a field geologist, preferably himself. He prepared for this task by comparing nuclear craters at the Nevada Test Site with the similar Arizona Meteor Crater, whose meteorite-impact origin he settled once and for all. This work earned Gene a Ph.D. from Princeton in 1960 and led to a rapid creative burst in which he demonstrated the impact origin of the lunar crater Copernicus; mapped the Copernicus region using the principles of terrestrial geologic field mapping, thereby originating mapping methods that are still in use; established a lunar stratigraphic timescale; proved (with E.C.T. Chao) the impact origin of the previously enigmatic Ries crater in Germany; established an Astrogeologic Studies Group within the USGS that was destined to take the lead in lunar studies; and gained international recognition for himself and his ideas at geological and astronomical conferences in Denmark and Russia. He accomplished all this before President Kennedy set the landing of a man on the Moon as the goal of Project Apollo, in May 1961.
Without Shoemaker's efforts, we would know little about the Moon's geology or, probably, much else about its nature. At NASA Headquarters during 1962 and 1963 he tenaciously and successfully lobbied for the addition of a vigorous scientific program featuring geology to Apollo's land-and-return goal. Barred by a faulty adrenal gland from personally stepping on the Moon, Shoemaker initiated and vigorously promoted the intensive geologic training of the astronauts that made them able scientific observers and reporters. He was a major investigator of the imaging by unmanned Ranger and Surveyor satellites which, before any Apollo landing, revealed the nature of the Moon's cover of soil and broken rock that he named the regolith. He led the field geology support teams for Apollos 11 and 12 but, disappointed with NASA's commitment to science, returned to academic life as Professor and Chairman of Caltech's Division of Geology and Planetary Sciences and to long-time interests in Earth's geology.
When spacecraft reached beyond the Moon, he focused on the satellites of the outer planets and on comets and asteroids, while enthusiastically and generously continuing to inspire, support, and guide the hundreds of scientists who are applying the methods he developed to whatever planets and moons come in view.
In the face of formidable doubt by advocates of volcanism, Shoemaker, along with Ralph Baldwin, established the impact origin of craters on the Earth and Moon. He also led in alerting society to the danger posed by comets and asteroids.
Although considered the fountainhead of planetary geology, the ever-curious and multitalented Shoemaker also became a planetary astronomer (while affiliated with the USGS and Lowell Observatory) as he and his wife Carolyn scanned the sky from Palomar Mountain for the Solar System's smaller bodies. He lived to see fragments of one comet they codiscovered, Shoemaker-Levy 9, strike the face of Jupiter in the first natural impacts ever observed in real time.
Eugene Shoemaker's well-lived life ended in a car crash in Australia in July 1997, while he and Carolyn once again, and with great joy, were reading the record of chance encounters between Earth's rocks and the rocks that travel the depths of space.
During his lifetime Shoemaker was recognized by at least 25 awards, including election to the National Academy of Sciences in 1980; the Day Medal of the Geological Society of America, awarded in 1982; the National Medal of Science, presented personally by President George Bush in 1992; and the American Geophysical Union's Bowie Medal, awarded in 1996. He was elected an AGU fellow in 1971 and served as President of the Planetary Sciences Section (1968-1970).
Don E. Wilhelms
Monte Rio, California