14 DAY TRIAL // Often called the Morning Star or the Evening Star, Venus is the second-closest planet to the Sun, and the brightest natural object in the visible part of space in the night sky, except for the Moon.
ESA's Venus Express mission provided new insights into the noxious atmosphere of Earth's sister planet.
Venus' atmosphere represents a true puzzle for scientists. Winds are so powerful and fast that they circumnavigate the planet in only four Earth days - the atmospheric "super-rotation" - while the planet itself is very slow in comparison, taking 243 Earth days to perform one full rotation around its axis.
At the equator, the extremely violent winds of the super-rotation are in constant 'battle' with other kinds of local turbulences, or 'regional' winds, creating very complex cloud structures.
At the poles, things get really complicated with huge double-eyed vortices providing a truly dramatic view. In addition, a layer of dense clouds covers the whole planet as a thick curtain, preventing observers using conventional optical means from seeing what lies beneath.
There are still many questions about what causes its violent winds and turbulences, and whether the surface topography is playing a role in the complex dynamics of the atmosphere.
Being capable of looking through the atmosphere at different depths, by probing it at different infrared wavelengths, the Ultraviolet, Visible and Near-Infrared Mapping Spectrometer (VIRTIS) on board is continuing its systematic investigation of Venus' atmospheric layers to solve the riddle of the causes for such turbulent and stormy atmosphere.
Scientists are currently trying to understand if there is any mechanism other than "convection" responsible for the equatorial turbulences, both on the day- and night-side of Venus, since on the night-side there is obviously no flux from the Sun, but the clouds' shape and the wind dynamics are somehow similar to that we see on the day-side.
Actually, the Venusian topography may play an important role also in the global atmospheric dynamics, since Alpha Regio, an area close to the equator, is characterized by a series of troughs, ridges, and faults that are oriented in many directions, with surface features that can be up to 4 kilometers high, presenting interesting cloud formations and storms, just above it.
Understanding this surface-atmosphere connection is one of the major objectives of Venus Express - something to be verified in the whole course of the mission.