Dr. Hunten and his colleagues at the University of Arizona will continue a program of theoretical study of planetary atmospheres and that of Earth from a planetary viewpoint, largely based on spacecraft and remote observations. With prior NSF grants, Dr. Hunten has worked on the atmospheres of Titan, Moon, Mercury, Uranus, Triton, and Mars, and on micrometeoroid entry at Uranus and Earth. Many of the specific problems to be addressed with the current grant grow out of these prior studies. Two of them are of particular interest: (1) An attempt to understand the tenuous atmospheres of Moon and Mercury by studying the interaction of atoms with the surface, and (2) Study of preservation of micrometeoroids entering the Earth's atmosphere, by aerocapture in the thermosphere.
