Named in honor of Clair C. Patterson {1922–1995}, geochemist at the California Institute of Technology. Patterson is world-renowned for his determination, through exquisite techniques of isotopic analysis, of the age of the Earth and of meteorites at 4.55 × 109 years; with the aid of additional lines of evidence, this can be shown to be the age of the solar system as a whole. He also played a leading role in revising the estimates of elemental abundances in various solar system materials. (M 6955) _ _.