Close-up View over Venus's South Polar Vortex
Date: 12 July 2006
Satellite: Venus Express
Depicts: South polar vortex at 5.05, 4.65 and 4.08 micron
Copyright: ESA/VIRTIS/INAF-IASF/Obs. de Paris-LESIA
This triple image provides a close-up view of the double-eyed vortex at Venus's south pole, as seen by the Ultraviolet/Visible/Near-Infrared spectrometer (VIRTIS). The images were taken on 29 May 2006, at a distance of about 64 000 kilometres from the planet.
The vortex is imaged at different infrared wavelengths, corresponding to different atmospheric depths. The left image - taken at 5.05 μm - corresponds to an atmospheric altitude of about 59 kilometres, just about at the Venusian cloud deck. The central image - taken at 4.65 μm - corresponds to an atmospheric altitude of about 60 kilometres. The right image - taken at 4.08 μm - corresponds to an altitude of about 65 kilometres, just in the upper clouds. The images were taken with a 20° inclination with respect to vertical pointing.
The brighter the colour, the more radiation is coming from the hot layers below. The brightest spot corresponds to the centre of the vortex, where radiation from the deeper layers becomes clearly visible.
The dark circular structures surrounding the brighter area belong to the big vortex structure (bottom of the images) - 2500 kilometres across - and are part of the planet's atmospheric super-rotation. The left image also clearly shows a complex structure, with many more small sub-structures visible.
Under related images on the right hand side, are two animated sequnces. The first, "Close-up View over Venus's South Polar Vortex", shows several images all taken at 5.05 μm. The second, "Venus's South Polar Vortex", is a sequence of images taken at different infrared wavelengths but all of the same south polar region.
