Untitled Document
NASA/JPL/Cassini/University
of Arizona
Many pictures of Jupiter
reveal its cloud
bands, the Great
Red Spot, and other large weather features. But nearer to its poles, the
gas giant planet takes on a different and inexplicable look.
This picture, taken by the
Cassini spacecraft before it flew past Jupiter en route to Saturn, reveals the
intricate structures of the northern Jovian clouds. The colors are true, but
the Cassini imaging team enhanced the contrast to bring the strange features
out.
The different structures
are clouds of different chemical composition, different height, and different
thicknesses. While winds at Jupiter's equator can exceed 300 mph (483 kilometers
per hour), they are less severe nearer the poles. Yet wind near the poles tends
to swirl more, in vortex motions. Nobody
knows why.
One possible explanation
is that compared to Earth, where the Sun's energy is the root of all wind, Jupiter's
clouds are more effected by heat generated internally. The internal heat might
be greater near the poles, scientists say, which would create more convection
there. This rising action would then generate more vortexes, just as rising
air on Earth creates tornadoes
and hurricanes.
The spacecraft was 11.8million
miles (19.0 million kilometers) away when it collected the data for this image
on Dec. 13, 2000.
-- Robert
Roy Britt
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