PROBING PLANETARY-ATMOSPHERES WITH STELLAR OCCULTATIONS

Earth-based stellar occultations probe the temperature, pressure, and number-density profiles of planetary atmospheres in the microbar range with a vertical resolution of a few kilometers. Depending on the occu ltation data available for a given body and other information, the tec hnique also allows determination of local density variations, extincti on by aerosols and molecules, rotation period and zonal winds, atmosph eric composition, and the temporal and spatial variability of an atmos phere. A brief quantitative description of the interaction of starligh t with a planetary atmosphere is presented, and observational techniqu es are discussed. Observational results through 1995 are presented for Venus, Mars, Jupiter, Saturn, Titan, Neptune, Triton, Pluto, and Char on.