Planetary atmospheres

Four years is approximately the doubling time for knowledge of extra-terrestrial planetary atmospheres. During 1975–8 the results of several important missions to Venus, Mars, Jupiter and its satellites were analyzed, and during 1979 more spacecraft will arrive at Jupiter and Saturn. Spacecraft data are supplemented by ground-based observations, often at higher spectral resolution and extending over longer periods of time. As a result of this rapid growth of information, many first-order questions concerning the composition, physical state and kinematics of planetary atmospheres have been answered