Abstract: The D2/D1 ratio observed for the sodium emission around Io appears too large for that emission to be only resonant scattering of the solar flux. An optically thick source close to the surface of Io, with an intensity ...

Abstract: High-dispersion photoelectric spectra have been taken of four oxygen A band lines. Synthetic spectra have been calculated, and ratios of the Martian spectra with the synthetic spectra have been taken to enhance any possible ...