Infrared Polar Emissions
This composite image shows six infrared views of Venus as seen by the Ultraviolet/Visible/Near-Infrared spectrometer (VIRTIS) on board ESA’s Venus Express spacecraft between 12 and 19 April 2006, during the first orbit, or ‘capture orbit’, around the planet.
The images (taken at 5 microns) were obtained at six different time slots and at different distances from Venus: 1, 2, 3, 4, 5, 6.
The infrared radiation coming from Venus was converted in this reddish colour scheme. Thermal radiation comes from the lower atmosphere, (just above the cloud top, located at about 60 kilometres altitude). Solar radiation reflected by the upper atmospheric layers (roughly between 60 and 80 kilometres altitude) and thermal radiation from the layers below contribute to the brightest part of the image.
The south polar vortex structure is visible from different view points close to the centre of the images, mostly in the dark side.