Harold Urey's Lunar Landing Sites (1961)

My graduate research professor, Paul K. Kuroda lectured often on some of Harold Urey's work.  They corresponded frequently over three decades.  Professor Urey was the scientist who coined the term "cosmochemstry" for the new discipline in the 1950s concerning the science of geochemistry as applied to extraterrestrial bodies.

Much of Kuroda's research was focused on the origin of the chemical elements and the mysterious isotopic anomalies of xenon in meteorites, which is a specialized area of cosmochemistry.  There was a lot of interest in the xenon isotopic distribution in lunar materials, which was compared to terrestrial and meteorite minerals.  Kuroda was able to predict the existence of extinct Pu-244 in the early solar system based on mass spectroscopic analysis of stable fission products in meteorites in the 1960s.