Bob Clayton passed away on Dec. 30, 2017, after several years of declining health at his home in Michigan City, Indiana, surrounded by family. Bob was the Meteoritical Society’s 1982 Leonard Medalist. He was born on March 20, 1930, in Hamilton, Ontario, Canada. He received his B.S. and M.S. degrees from Queen’s University, Ontario, and his Ph.D. from Caltech (1955) mentored by Samuel Epstein. He joined the Chemistry Department and the Enrico Fermi Institute (1958), and then the newly founded Department of Geophysical Sciences (1961) at The University of Chicago. He was the Enrico Fermi Distinguished Service Professor until he retired in 2001, remaining active in emeritus status until about 2014. More…