Nov. 29, 2007
Venus Express is the first mission dedicated to the study of the composition and dynamics of the planet’s atmosphere. The European orbiter has identified broad meteorological regimes, all influenced by the gigantic hurricane-like vortices at the poles. From these double-eyed vortices, swirling in the atmosphere, around the planet in just a couple of days, to smoother streams at mid-latitudes and wave-dominated phenomena at lower latitudes - these regimes are, surprisingly, clearly delineated. The spacecraft’s elongated orbit has allowed its instruments, notably the VMC camera and the VIRTIS imaging spectrometer, to obtain long-shot views of the planet’s weather patterns, mosaics showing different types of cloud formation and wind speeds, varying according to altitude and latitude. Venus Express has obtained much information on the composition and physical processes active in the atmosphere, and has been able to measure the loss of molecules, stripped away by the solar wind. Rates of oxygen depletion are still being calculated but some tentative conclusions are being advanced. Venus Express has also probably brought the final answer to the controversy about the presence of lightening. The venusian picture is still far from complete. The European mission which has now been prolonged to the end of 2008, is pursuing its harvest of data, allowing scientists to better understand the precise reasons why, compared to our planet, Venus has become so inhospitable.
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