for National Geographic News
Saturn boasts cyclones at each of its poles that dramatically outpower Earth-roving hurricanes, new images reveal.
The Cassini spacecraft—a cooperative project of NASA, the European Space Agency, and the Italian Space Agency—recently peered below what had previously appeared to be isolated cumulus clouds at the planet's south pole.
"What looked like puffy clouds in lower resolution images are turning out to be deep convective structures seen through the atmospheric haze," Cassini imaging team member Tony Del Genio said in a press release.
"One of them has punched through to a higher altitude and created its own little vortex."
"Little" is relative—the eye of the storm is surrounded by an outer ring of clouds that measures 2,500 miles (4,000 kilometers) wide. That's about five times the size of the largest cyclones, or hurricanes, on Earth.
(Related: "Nonstop 'Hurricane' Raging on Saturn's South Pole" [March 27, 2008].)
In addition, the Cassini craft found a never-before-seen cyclone at Saturn's north pole.
This storm is visible only in near-infrared wavelengths, because the north is too dark right now for visible-light cameras.
Time-lapse movies show the whirlpool-like cyclone at the north pole is rotating at 325 miles (530 kilometers) an hour—more than twice the speed of Earth's fastest hurricanes.
On Earth, powerful storms are driven by warm surface temperatures, which allow moist air from the oceans to rise and condense.
But without large bodies of liquid water, Saturn's polar cyclones are likely fed by heat from thunderstorms deep in its ammonia-filled atmosphere, said Kevin Baines, a Cassini scientist on the visual and infrared mapping spectrometer team.
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