Double vortex at Venus South pole

This video is composed by six sequences of images (in false colour) taken 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 sequences (taken at 5 microns) were obtained during six different time slots and at different distances from Venus:

• 12 April: from 210 000 kilometres
• 13 April: from 280 000 kilometres
• 14 April: from 315 000 kilometres
• 16 April: from 315 000 kilometres
• 17 April: from 270 000 kilometres
• 19 April: from 190 000 kilometres

The planet’s globe, imaged at different angles, was mapped onto an electronic mock-up of Venus, so to have the South Pole always plotted at the centre of each single image.

Around the South pole it is possible to see a peculiar double-eye vortex structure, never clearly seen by any other Venusian mission before. The movie shows the rotation and the shape variation of the double vortex over time. It is also possible to see the rotation of the ‘terminator’, the line separating the day side – visible in yellow - from the night side.

The images also show the presence of a collar of cold air around the vortex structure (dark blue), possibly due to the recycling of cold air downwards.