In situ measurements of thermospheric composition, temperature, and winds by mass spectrometry

Mass spectrometry, in which a beam of electrons ionizes a sample of atmospheric gas and then analyses the ions thus produced to determine the concentration of each species in the sample, is presently evaluated as a basis for the study of earth atmosphere and other planetary atmospheres' properties. Recent applications of in situ mass spectrometry have measured thermospheric neutral gas composition, temperatures, and winds, with a spatial resolution sufficiently high to reveal previously unsuspected atmospheric variability. It is expected that analyses of these data will lead to a more detailed understanding of the deposition processes governing the thermosphere's highly variable structure.