Leonard Medal Citation for Robert M. Walker

The 1993 Leonard Medalist, Robert M. Walker, started his professional career during the 1950s, as a physicist studying radiation effects in solids. The work for which he is probably best known, the study of particle tracks in solids, began in the early 1960s at the General Electric Research Laboratories, in collaboration with R. L. Fleischer and P. B. Price. Many of us working in the field of meteoritics have had no formal training in geology. This is usually a handicap, but it proved to be important in launching the science of trackology. Muscovite mica was an important material in the early studies of particle tracks and, even today, is the optimum track detector in many respects.