Saturn’s Lightning Bolts 10,000 Stronger Than Those on Earth
“The electrostatic radio outbursts have waxed and waned in intensity for five months now,” said Georg Fischer, an associate with the radio and plasma wave science team at the University of Iowa, Iowa City. “We saw similar storms in 2004 and 2006 that each lasted for nearly a month, but this storm is longer-lived by far. And it appeared after nearly two years during which we did not detect any electrical storm activity from Saturn.”
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NASA’s mission of Cassini-Huygens has been tracking and observing Saturn’s electrical storm for the past five months or so, with scientists viewing the massive lightning bolts that are 10,000 times more powerful than any seen on Earth. Located earlier on December 6, 2008, this is a lightning-generated storm that is the longest observed electrical storm observed by Cassini so far to date with actual proof. Resembling an extra large terrestrial thunderstorm, it has a diameter of several thousands of miles producing radio signals a thousand times more powerful than any terrestrial thunderstorm ever produced.
These radio waves produced by the lightning flashes within the Saturn storm, called Saturn electrostatic discharges, were first observed and detected on Saturn by the radio and plasma wave science instrument on Nov. 27, 2007. But earlier, in 2004 and 2006, the Cassini had observed similar lightning storms that seemed to produce these lightning bolts from Saturn’s own internal heat. And before that, NASA’s two Voyagers listened to radio emissions from Saturn’s lightning storms for a couple of days, with the flybys arriving about nine months apart—which made NASA scientists theorizing that the lightning storm may have lasted a year.
The Saturn lightning storm occupies the same volume of space as the troposphere of Earth, an atmospheric area that has an altitude of 15 km which is where the weather begins to occur. “It’s absolutely huge,” Fischer told New Scientist. “Imagine you have lightning on Earth everywhere - that’s how you could compare it.” Even though the storm has lasted five months, it seems to have varying power. “It seems that every 10 to 14 days there’s a kind of enhancement, then for one week to 10 days, it is less intense.”
This five-month storm is located in “Storm Alley” in Saturn’s southern hemisphere, where the storm is detected every 10 hours and 40 minutes. This is detected by Cassini’s radio plasma wave instrument when the planet rotates into view, with the storm giving off a radio pulse every few seconds or so, lasting for a tenth of a second—a typical time frame for electrical discharges. “Since Cassini’s camera cannot track the storm every day, the amateur data are invaluable,” said Fischer. “I am in continuous contact with astronomers from around the world.”
This entry was posted on Monday, April 28th, 2008 at 7:02 pm and is filed under Mission Objectives, Space Agency News. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.
