"It's polar and it's stationary, so it doesn't move around like hurricanes on Earth," study co-author Dyudina said.
"On Earth, hurricanes usually drift toward the pole and then crash into land."
Because hurricanes draw their energy from heat evaporation over warm ocean waters, they fade away on land.
Saturn has no land to interfere with the storm's power source. It also has no liquid oceans, so the storm gathers energy in a different way than Earth's hurricanes.
Perpetual Tempest?
Since 2003, Dyudina said, the tempest doesn't appear to have changed in any way detectable by NASA's Cassini spacecraft, which first spotted the storm.
Scientists aren't sure how long the storm has been raging, or how long it will last.
It may be a seasonal occurrence. But because of Saturn's long orbit, the planet's year lasts 30 Earth years. It has been fall in Saturn's southern hemisphere since observations began five years ago.
While it lasts, University of Louisville's Dowling said the storm's eye offers a unique look at Saturn's ammonia clouds.
"The fact that we can see down into the well of this eye is itself a revelation," Dowling explained.
"Because Saturn has no land—no place to stand—no atmospheric chemist or dynamicist has ever seen before how the abyssal cloud decks look and act."
Saturn's Past
Scientists also hope that the storm can shed light on Saturn's past—specifically, how Saturn has been cooling since it contracted into a planet from gas and dust billions of years ago.
"How does heat from the [planet's] interior get up into space?" Dyudina said.
Earth's hurricanes use the evaporation of water and clouds to transfer heat away from the planet's surface.
"If we see similar things on Saturn [and the vortex] is a mechanism for how the heat gets through the clouds to space, that would raise interesting questions about the mechanisms of cooling of this planet," she said.
"That tells us about Saturn's role in the evolution of the solar system."
(Related: Saturn's Rings as Old as Solar System, Study Says [December 13, 2007].)
Dowling also noted that the storm could help hurricane forecasters on Earth.
By comparing multiple eye-wall formations on Saturn and on Earth, where such structures are not fully understood, scientists may be able to better predict hurricane movements and durations, he said.
|
SOURCES AND RELATED WEB SITES
|
