惑星大気の構造

火星・金星ロケットデータを中心に

抄録

Mariner 4, 5 and Venera 4 observed the atmospheric structure, temperature, pressure, and composition in the lower atmospheres and airglow, electron distribution, and exosphere temperature in the upper atmospheres and ionospheres of Venus and Mars, by using various kinds of technique. The principles and results of the measurements are critically summarized, taking also into account the results of the ground-based observation. It is emphasized that the physics and chemistry of the atmospheric processes are not yet understood well. As an example, the dispute on the interpretation of the observed electron density profiles in the Cytherean and Martian ionospheres is described in detail. A theory which explains various data at hand in a consistent manner has been developed, but its justification may remain in future. Finally, the plans for the future space probe mission are introduced in brief.