This grant provides continued support of the UCLA ion microprobe laboratory as a national facility for research in the earth and planetary sciences. It enables access to the facility by qualified external investigators. In addition, it permits: (1) Further development of analytical methods that take advantage of the unique strengths of SIMS for in situ analyses of isotopic abundances relevant to problems in geochemistry and geochronology; (2) Hardware upgrades to critical components of the UCLA CAMECA ims 1270 that will significantly extend its life as a state-of-the-art instrument; and (3) Development of an education and outreach program focused upon K-12 students and teachers and establishment of a summer intern program for UCLA undergraduates. Partnerships are established with the NASA Astrobiology Institute and with the California Science Project in order to leverage education and outreach opportunities. Data produced from the UCLA national ion microprobe facility have led to an array of significant discoveries in fields ranging from tectonics and igneous processes to sedimentary processes, paleoclimatology and paleobiology, the earliest history of the Earth and the origin and early evolution of the Solar System that have been detailed in 120 scientific articles since 1995. Presently, nearly three dozen NSF-supported projects are reliant upon the facility to conduct research in these diverse fields. Based upon current interest levels, we expect that the unique capabilities of the high-resolution ion microprobe will remain in high demand in the coming years. ***