Observations Of Huge Storm On Saturn
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Today the European Southern Observatory and NASA’s JPL announced their findings from a joint survey of an extremely large storm in Saturn’s northern hemisphere. The storm nearly stretches around the entire planet and has been sending plumes of gas high into the planet’s atmosphere since December 2010.
Saturn in visible light (Left) and as observed in Infrared by ESO's Very Large Telescope (Center/Right) – Image Credit: ESO/University of Oxford/L. N. Fletcher/T. Barry
The atmospheric disturbance was first detected by Cassini’s radio and plasma wave instruments, as well as amateur astronomers who tracked the disturbance visually starting in December, 2010. During the storm’s expansion, the core developed into a thunderstorm and a roughly 5,000 km wide dark vortex, thought to be similar to Jupiter’s Great Red Spot.
“Nothing on Earth comes close to this powerful storm,” says Leigh Fletcher, the lead author and a Cassini scientist at the University of Oxford. “A storm like this is rare. This is only the sixth one to be recorded since 1876, and the last was way back in 1990.”
“Our new observations show that the storm had a major effect on the atmosphere, transporting energy and material over great distances, modifying the atmospheric winds — creating meandering jet streams and forming giant vortices — and disrupting Saturn’s slow seasonal evolution,” said Glenn Orton, co-author, at NASA/JPL.
The storm has been the strongest atmospheric disturbance ever detected in Saturn’s stratosphere. The discovery surprised researchers, since what had started as an ordinary disturbance deep in Saturn’s atmosphere made it’s way through cloud cover to the stratosphere. “On Earth, the lower stratosphere is where commercial airplanes generally fly to avoid storms which can cause turbulence,” says Brigette Hesman, a scientist at the University of Maryland in College Park who works on the CIRS team at Goddard and is the second author on the paper. “If you were flying in an airplane on Saturn, this storm would reach so high up, it would probably be impossible to avoid it.”
Researchers have dubbed some of these disturbances “stratospheric beacons”. The name is due to the strong temperature changes in the Saturnian stratosphere, about 300 km above the cloud tops of the lower atmosphere. Normal temperatures in Saturn’s stratosphere are around -130 degrees Celsius and the “beacons” are around 20 degrees warmer. These beacons cannot be detected in visual light, but easily outshine the rest of Saturn in the infrared portion of the electromagnetic spectrum. Not having been detected before, researchers are unsure at this time if the features are common to storms such as the one currently studied.
Details of the team’s findings will be published in this week’s edition of Science Magazine.
Source(s):European Southern Observatory Press Release, NASA/JPL Press Release
Ray Sanders is a Sci-Fi geek, astronomer and blogger. Currently researching variable stars at Arizona State University, he writes for Universe Today, The Planetary Society blog, and his own blog, Dear Astronomer
2012-12-04 08:06:03
Source: http://www.dearastronomer.com/2011/05/19/observations-of-huge-storm-on-saturn/
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