for National Geographic News
Earth's hurricane seasons may be dangerous, but at least they're temporary. On Saturn, the storm apparently never stops.
A massive tempest that's nearly the size of our planet has been howling above Saturn's south pole since it was first detected in 2003.
"We're inclined to say that it's like a hurricane," said Ulyana Dyudina, a planetary scientist at the California Institute of Technology in Pasadena and co-author of a new study on the storm.
The squall has a cyclone-like eye, about 2,600 miles (4,200 kilometers) in diameter that's surrounded by two towering walls of swirling clouds about 20 to 45 miles (30 to 70 kilometers) high.
The research on the storm will be published tomorrow in the journal Science.
(Related: "Huge Storm Spotted on Saturn" [February 16, 2006].)
The gas-giant planets host hundreds of storms. Some, like Jupiter's Great Red Spot, are even larger than Saturn's polar vortex. But none of the others visually resemble an earthly cyclone.
"The similarities are remarkable, especially the shadow cast by the eye wall—just like in a Category 5 hurricane on Earth," said Timothy Dowling, who directs the Comparative Planetology Laboratory at the University of Louisville and was unaffiliated with the new research.
A Category 5 is the most powerful type of storm on the Saffir-Simpson scale.
The storm also spins the same direction (clockwise) that Saturn spins on its axis—another hurricane-like trait—and its winds scream at some 350 miles an hour (550 kilometers an hour).
In some major respects, however, the Saturn storm is unique—and puzzling.
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