This beautiful composite is made of images obtained by the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) on board ESA’s Venus Express on 13 May 2007 at 1.27 and 1.7-micrometre wavelengths. The imaging distance from the planet varies from 62 000 km (top left) to 49 000 km (down right).

The blue part indicates the oxygen-airglow emission at 95-km altitude over the planet’s surface, while the yellow part indicates the underlying clouds situated at about 45-50 km over the surface. The composite illustrates how the airglow evolves over one Venus Express orbit (about 24 hours).
High-resolution versions of the individual images:
18_VIRTIS_oxygen_airglow_composite_1, 18_VIRTIS_oxygen_airglow_composite_2, 18_VIRTIS_oxygen_airglow_composite_3, 18_VIRTIS_oxygen_airglow_composite_4