Venusian Turbulence: the Alpha Regio Area

This image of the Venusian South Polar Region was acquired on 24 September 2006 by the Ultraviolet, Visible and Near-Infrared Mapping Spectrometer (VIRTIS) on board ESA’s Venus Express, from a distance of about 65.000 Km from the Planet’s surface.
The image, showing a complex cloud system, was taken on the night-side of Venus (04:00 Local Time - V.L.T.), at a wavelength of 1,7 micron that allows viewing the deep atmospheric layers. The field of view covers an area located at approximately 20° West Longitude (diagonal top left to bottom right), spanning from the Equator (at the horizon on the right) to 60° Southern Latitude (top left corner of the image).

The grey-scale of the image is such that black means more transparency, therefore less clouds, while white means more opacity, therefore more cloud concentration.

The Alpha Regio area is at the bottom left of the image. This area is characterised by a series of troughs, ridges, and faults that are oriented in many directions, with surface features that can be up to 4 kilometres high. It is not yet clear if atmospheric turbulences may be induced by the rough topography below the clouds.