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curiousuburb
Antimatter Man
 
Join Date: May 2004
Location: that interweb thing
 
2006-06-28, 18:32

Atmospheric Double Vortex discovered at Venusian South Pole.

Sulfuric Acid hurricanes are bad, mmmkay?


Quote:
Double vortex at Venus South Pole unveiled!

27 June 2006
ESA’s Venus Express data undoubtedly confirm for the first time the presence of a huge 'double-eye' atmospheric vortex at the planet's south pole. This striking result comes from analysis of the data gathered by the spacecraft during the first orbit around the planet.

On 11 April this year, Venus Express was captured into a first elongated orbit around Venus, which lasted 9 days, and ranged between 350 000 and 400 kilometres from Venus' surface. This orbit represented for the Venus Express scientists a unique opportunity to observe the planet from large distances. This made it possible to obtain first clues about the Venusian atmospheric dynamics on a global scale, before the spacecraft got closer and started observing the planet in greater detail.

During this first orbit – called the 'capture orbit' – some of the Venus Express instruments were used to perform the first observations at different distances from Venus, for a few hours per time on six different slots between 12 and 19 April 2006.

Venus's southern hemisphere in infrared

Amazing infrared, visible and ultraviolet images of the Venusian globe already reveal several atmospheric features of great interest. The most striking of these is a huge, double-eye atmospheric vortex over the south pole, not dissimilar from the equivalent structure present at the north pole – the only one previously studied in some detail.

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This video is composed by six sequences of images (in false colour) taken by the Ultraviolet/Visible/Near-Infrared spectrometer (VIRTIS) on board ESA’s Venus Express spacecraft between 12 and 19 April 2006, during the first orbit, or ‘capture orbit’, around the planet.

The sequences (taken at 5 microns) were obtained during six different time slots and at different distances from Venus:

12 April: from 210 000 kilometres
13 April: from 280 000 kilometres
14 April: from 315 000 kilometres
16 April: from 315 000 kilometres
17 April: from 270 000 kilometres
19 April: from 190 000 kilometres

The planet’s globe, imaged at different angles, was mapped onto an electronic mock-up of Venus, so to have the South Pole always plotted at the centre of each single image.

Around the South pole it is possible to see a peculiar double-eye vortex structure, never clearly seen by any other Venusian mission before. The movie shows the rotation and the shape variation of the double vortex over time. It is also possible to see the rotation of the ‘terminator’, the line separating the day side – visible in yellow - from the night side.

The images also show the presence of a collar of cold air around the vortex structure (dark blue), possibly due to the recycling of cold air downwards.

Last edited by curiousuburb : 2006-06-28 at 18:37.
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