The Meteoritical Society will present the Leonard Medal to the University of Chicago’s Lawrence Grossman for his research on how minerals condensed from hot gases in the early solar system.
Grossman will receive the Leonard Medal next July at the society’s annual meeting in Nancy, France. The Leonard Medal honors outstanding contributions to the science of meteoritics and closely allied fields. It is named for the society’s founding president, Frederick C. Leonard, a 1918 University of Chicago graduate.
As a cosmochemist, Grossman conducts research on the origin of solid matter in the solar system. His research is aimed at learning how the sun and planets formed approximately 4.5 billion years ago.
A University of Chicago faculty member his entire career, Grossman completed his Ph.D. in geochemistry at Yale in 1972. Early in his career, he collaborated with a Chicago colleague in researching lunar samples collected during NASA’s Apollo 15 mission to the moon.
He has devoted most of his career to the study of meteorites, pieces of asteroids that have fallen to Earth. These include the meteorite fragments that showered Park Forest, Ill., and nearby communities on the evening of March 26, 2003. Witnesses from surrounding states reported seeing the fireball that the meteorite produced as it entered the atmosphere.
Grossman also was among the first scientists to examine samples of Comet Wild-2, which NASA’s Stardust spacecraft collected and returned to Earth in January 2006. Along with 74 other scientists, Grossman co-authored the first detailed description of the comet in the Dec. 15, 2006, issue of the journal Science.
Cosmochemists have long suspected that comets formed in the coldest, far reaches of the solar system. But the Stardust mission yielded samples that probably formed under a wider range of temperatures than would be possible in the outer solar system alone. Grossman and Steven Simon, Senior Research Associate in Geophysical Sciences at the University of Chicago, contributed findings to the report, indicating that the mineralogy and chemical composition of the comet was similar to those found in a type of meteorite called carbonaceous chondrites.
Like comets, carbonaceous chondrites are believed to have survived relatively unchanged since the birth of the solar system. Unlike carbonaceous chondrites, however, the samples from Comet Wild-2 lacked water-bearing minerals.
Grossman’s many honors include the Geochemical Society’s F.W. Clarke Medal in Cosmochemistry in 1974 and the American Geophysical Union’s James B. Macelwane Award in 1980. He was elected to the Royal Society of Canada in 1998. The International Astronomical Union named Asteroid 4565 Grossman in his honor in 2000.
Previous University of Chicago recipients of the Leonard Medal include Edward Anders, the Horace B. Horton Professor Emeritus in Chemistry, and Robert Clayton, the Enrico Fermi Distinguished Service Professor Emeritus in Chemistry. Nobel laureate Harold Urey, a Chicago faculty member from 1945 to 1958, became a Leonard Medalist after leaving the University.
