January 31, 2013
Storm Engulfs Saturn, Then Itself, Ending Its 6-Month Reign
Lee Rannals for redOrbit.com — Your Universe Online
Cassini mission scientists have observed a huge thunder-and-lightning storm on Saturn consume itself for the first time.The NASA scientists said in a paper published in the journal Icarus that they observed as the massive storm made its way around the planet, until it ran into its own tail and dissipated.
"This Saturn storm behaved like a terrestrial hurricane - but with a twist unique to Saturn," Andrew Ingersoll, a Cassini imaging team member based at the California Institute of Technology, Pasadena, said in a statement. "Even the giant storms at Jupiter don't consume themselves like this, which goes to show that nature can play many awe-inspiring variations on a theme and surprise us again and again."
The storm on Saturn was first detected on December 5, 2010, and NASA used Cassini's radio and plasma wave subsystem and imaging cameras to keep track of it as it made its way around the northern hemisphere.
In just a few months, the storm had wrapped itself around the planet at 33 degrees north latitude, stretching about 190,000 miles in circumference. As the storm head progressed, engulfing the planet, it eventually became its own demise, running into its vortex in June 2011. After this, the monstrous storm faded away.
Cassini's infrared detectors have continued to track some of the lingering effects left by the storm in Saturn's troposphere, which is the higher layers of its atmosphere.
"This thunder-and-lightning storm on Saturn was a beast," Kunio Sayanagi, the paper's lead author and a Cassini imaging team associate at Hampton University in Virginia, said in a statement. "The storm maintained its intensity for an unusually long time."
Sayanagi said the storm head thrashed for 201 days and its updraft was so strong, it would have sucked the entire volume of Earth's atmosphere in 150 days.
"And it also created the largest vortex ever observed in the troposphere of Saturn, expanding up to 7,500 miles across," Sayanagi added.
The vortex grew to be as large as a giant storm located on Jupiter known as Oval BA, not to be confused with the Great Red Spot storm. However, both of these storms on Jupiter are not known as thunder-and-lightning storms, as witnessed on Saturn.
"Cassini's stay in the Saturn system has enabled us to marvel at the power of this storm," explained Scott Edgington, Cassini's deputy project scientist at NASA's Jet Propulsion Laboratory in Pasadena, California. "We had front-row seats to a wonderful adventure movie and got to watch the whole plot from start to finish."
He said that this data will enable scientists to gain a better understanding of weather patterns around our Solar System, and learn about what sustains and extinguishes these gargantuan storms.
NASA said the storm was the longest running of the storms that have appeared in Saturn's northern hemisphere once every 30 Earth years. The longest-lasting storm on Saturn was located in the planet's southern hemisphere, and it lasted over 334 days. However, this long-lasting storm was 100 times smaller than the area the recent thunderous-northern-hemisphere storm was.
Last year, redOrbit reported about how Cassini embarked on its 15th year of being a veteran spacecraft. The NASA spacecraft has not only yielded great insight into our Solar System's amazing ringed planet, but it has also given scientists extraordinary views of Saturn's moons.
Cassini has recently provided scientists with a great tool in observing Titan, revealing that the moon may hold liquid water beneath its ice-ridden shell.