Talk about flying close to the wind. A Japanese interplanetary spacecraft will begin its travels to Venus next week, to get the clearest ever view of massive gusts in the planet鈥檚 atmosphere.
The Venus Climate Orbiter, called , aims to find out why blistering winds zip around the planet at speeds of up to 400 kilometres per hour. The upper clouds can circle the planet in four days or even less, and no one knows why. The effect is called 鈥渟uper-rotation鈥�, because the bulk of the atmosphere is rotating much faster than the planet itself. Venus takes 243 Earth days to make one rotation.
To investigate, AKATSUKI will move roughly in sync with the winds during part of its orbit, so it can track a patch of atmosphere for about 24 hours at a stretch. Five cameras will snap the planet at different wavelengths. 鈥淏y combining the images from these cameras we can develop a three-dimensional model of the Venus atmosphere,鈥� says mission scientist Takeshi Imamura. This will be the first time such measurements have been taken on a planet other than Earth, he adds.
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AKATSUKI will be particularly well equipped to study slower winds that move north and south from the planet鈥檚 equator, which may well play a significant role in the atmosphere鈥檚 rotation. The European Space Agency鈥檚 Venus Express, which is in orbit around the planet, can already see these meridional winds. 鈥淏ut the error bars are quite wide,鈥� says ESA鈥檚 H氓kan Svedhem. 鈥淲e can鈥檛 really tell anything about the seasonal or day-to-day variability.鈥�
Plans for joint observations using the two spacecraft are in the works.
