Named in memory of James B. Pollack (1938–1994), a planetary scientist who spent much of his career at the NASA Ames Research Center. He was a world leader in the study of planetary atmospheres and particles using radiative transfer techniques. His work was highly creative and interdisciplinary, and it led to numerous advances in our understanding of the solar system. He played major roles in many NASA flight missions from Mariner 9 to Cassini and guided numerous young planetary scientists into productive careers. Work on the effects on the earth’s atmosphere and surface biology of the Cretaceous-Tertiary impactor led Pollack and others to the concept of “nuclear winter”. (M 25653) _ _.