The bright big spot on the left of the image corresponds to an area where the cloud deck is thinner. Such regions, similar to large holes, allow the thermal radiation from below the clouds layer to increase significantly with respect to the surrounding areas, and make it possible to probe very deep in the atmosphere with a limited attenuation from the clouds.


 
This artist's impression shows Venus Express focussing on studying the peculiar atmosphere of Venus, with a precision never achieved before. In doing so, the mission is making the first ever use of the so called 'infrared windows' present in Venus' atmosphere; they are narrow bands in the atmospheric spectrum, discovered in the 1980s thanks to ground observations. Looking through these 'windows' Venus Express is able to gather precious information about the lower layers of the atmosphere and even the surface.


 
This movie, built with infrared images taken by the Ultraviolet/Visible/Near-Infrared spectrometer (VIRTIS) on board ESA’s Venus Express, provides a close-up view of the double-eyed vortex at Venus south pole. The images (ranging from 4.5 to 5.1 microns) were taken on 29 May 2006, from a distance of about 64 000 kilometres from the planet.

Thanks to the use of different wavelengths, VIRTIS probed the atmosphere at different depths, ranging from 70 kilometres to about 60 kilometres altitude. It is interesting to see how the images contrast and the details increase while approaching the 60 kilometres altitude.


 
This night-side image of the southern hemisphere of Venus was taken by the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS) on board Venus Express on 29 July 2006, from a distance of about 64 000 kilometres over the surface (around the orbit apocentre), at a wavelength of 1.7 micrometres. The South pole is visible on the top left of the image.

This image provides a remarkable example of a wave structure, running from the bottom to the top-right, each ‘wave’ extending about 150 kilometres. This peculiar cloud feature is often seen at a latitude of about 55º South.

The picture also shows a part of the polar vortex (top left). Regions of thinner clouds are also present in this image. They are visible as bright spots (top left corner), as they allow more thermal radiation to escape towards deep space from the hotter regions below.

The region between the black stripe around the pole and the wave structure contains the so called ‘cold collar’, a region in which the temperature of the clouds is lower than that of the surrounding area.



Release date: 23 May 2007