Cosmochemistry is an interdisciplinary science that overlaps with geochemistry, geology, astronomy, astrophysics, and geophysics to discover the materials and fundamental processes in the solar nebula and our Solar System. Cosmochemistry research within SOEST involves studies of the raw materials that were the building blocks for the Solar System, including presolar grains from meteorites, interplanetary dust particles, and comet samples returned by the Stardust mission. Researchers and students investigate the timing of events during the formation of the Solar System through studies of short-lived radionuclides. Early Solar System processes are investigated through measurements of chemical compositions, trace-element abundances, isotopic fractionations, and the unique variations exhibited by oxygen isotopes.