Fluorescent emission of carbon dioxide at Venus

This image shows the fluorescent emission of carbon dioxide (CO2) from the upper atmosphere of Venus on the day side.
It was obtained by the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) on board ESA’s Venus Express on 15 May 2006, at a distance of about 65 000 km from the planet.

The fluorescence can be especially seen in the limb (red line surrounding the planet’s profile) where it shows very enhanced brightening, at around 120-km altitude.