The Red and Green Lines of Atomic Oxygen in the Nightglow of Venus

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O(1D) and O(1S), the excited states that give rise to the atomic oxygen red and green lines, are produced in the Venus nightglow in dissociative recombination of O2+. The emissions should also be excited by precipitation of soft electrons, the suggested source of the ''auroral'' emission features of atomic oxygen at 1304 and 1356 Å, which have been reported from observations of the Pioneer Venus Orbiter Ultraviolet Spectrometer. No emission at 6300 or 5577 Å was detected, however, by the visible spectrophotometers on the Soviet spacecraft Veneras 9 and 10 and upper limits have been placed on the intensities of these features. Here we evaluate the constraints placed on models for the auroral production mechanism by the Venera upper limits by modeling the intensities of the red and green lines in the nightglow. We combine a model for the vibrational distribution of O2+ on the nightside of Venus with rate coefficients recently computed by Guberman for production of O(1S) and O(1D) in dissociative recombination of O2+ from different vibrational levels. The integrated overhead intensities are 1 — 2 R for the green line and about 46 R for the red line.