This image is taken at a wavelength of 1.27 microns. It shows "airglow" emission from oxygen
molecules high in the Venus atmosphere on the night side of the planet. This emission arises when
CO2 molecules on the day side are dissociated by sunlight to give oxygen atoms that are then
carried by the upper atmosphere circulation to the night side where they combine to form oxygen
molecules in excited states. The airglow emission is highly variable, but is usually brightest near the
anti-solar point as shown here (the red and white region). In this case a strong plume of emission
extending across the disk is also seen. The overexposed sunlit crescent is on the right.