July 06, 2011

Dwayne C Brown Headquarters, Washington
202-358-1726 dwayne c brown@nasa gov

Jia-Rui Cook Jet Propulsion Laboratory, Pasadena, Calif 818-354-0850 jccook@jpl nasa gov

RELEASE: 11-220

CASSINI SPACECRAFT CAPTURES IMAGES AND SOUNDS OF BIG SATURN STORM

WASHINGTON -- Scientists analyzing data from NASA's Cassini spacecraft now have the first-ever, up-close details of a Saturn storm that is eight times the surface area of Earth

On Dec 5, 2010, Cassini first detected the storm that has been raging ever since It appears at approximately 35 degrees north latitude on Saturn Pictures from Cassini's imaging cameras show the storm wrapping around the entire planet covering approximately 1 5 billion square miles (4 billion square kilometers)

The storm is about 500 times larger than the biggest storm previously seen by Cassini during several months from 2009 to 2010 Scientists studied the sounds of the new storm's lightning strikes and analyzed images taken between December 2010 and February 2011 Data from Cassini's radio and plasma wave science instrument showed the lightning flash rate as much as 10 times more frequent than during other storms monitored since Cassini's arrival to Saturn in 2004 The data appear in a paper published this week in the journal Nature

"Cassini shows us that Saturn is bipolar," said Andrew Ingersoll, an author of the study and a Cassini imaging team member at the California Institute of Technology in Pasadena, Calif "Saturn is not like Earth and Jupiter, where storms are fairly frequent Weather on Saturn appears to hum along placidly for years and then erupt violently I'm excited we saw weather so spectacular on our watch "

At its most intense, the storm generated more than 10 lightning flashes per second Even with millisecond resolution, the spacecraft's radio and plasma wave instrument had difficulty separating individual signals during the most intense period Scientists created a sound file from data obtained on March 15 at a slightly lower intensity period

Cassini has detected 10 lightning storms on Saturn since the spacecraft entered the planet's orbit and its southern hemisphere was experiencing summer, with full solar illumination not shadowed by the rings Those storms rolled through an area in the southern hemisphere dubbed "Storm Alley " But the sun's illumination on the hemispheres flipped around August 2009, when the northern hemisphere began experiencing spring

"This storm is thrilling because it shows how shifting seasons and solar illumination can dramatically stir up the weather on Saturn," said Georg Fischer, the paper's lead author and a radio and plasma wave science team member at the Austrian Academy of Sciences in Graz "We have been observing storms on Saturn for almost seven years, so tracking a storm so different from the others has put us at the edge of our seats "

The storm's results are the first activities of a new "Saturn Storm Watch" campaign During this effort, Cassini looks at likely storm locations on Saturn in between its scheduled observations On the same day that the radio and plasma wave instrument detected the first lightning, Cassini's cameras happened to be pointed at the right location as part of the campaign and captured an image of a small bright cloud

Because analysis on that image was not completed immediately, Fischer sent out a notice to the worldwide amateur astronomy community to collect more images A flood of amateur images helped scientists track the storm as it grew rapidly, wrapping around the planet by late January 2011

The new details about this storm complement atmospheric disturbances described recently by scientists using Cassini's composite infrared spectrometer and the European Southern Observatory's Very Large Telescope The storm is the biggest observed by spacecraft orbiting or flying by Saturn NASA's Hubble Space Telescope captured images in 1990 of an equally large storm

The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency NASA's Jet Propulsion Laboratory in Pasadena manages the mission for the agency's Science Mission Directorate in Washington The radio and plasma wave science team is based at the University of Iowa, Iowa City, where the instrument was built The imaging team is based at the Space Science Institute in Boulder, Colo

For images and an audio file of the storm, visit:

http://www nasa gov/cassini

-end-

To subscribe to the list, send a message to: hqnews-subscribe@mediaservices nasa gov To remove your address from the list, send a message to: hqnews-unsubscribe@mediaservices nasa gov

The following information is a reminder of your current mailing list subscription:

You are subscribed to the following list: [list_name]

using the following email: example@example.com

You may automatically unsubscribe from this list at any time by visiting the following URL:

https://aus-city com/cgi-bin/dada/mail cgi/u/NASA_REPORTS/example/example com/

If the above URL is inoperable, make sure that you have copied the entire address Some mail readers will wrap a long URL and thus break this automatic unsubscribe mechanism

You may also change your subscription by visiting this list's main screen:

<[program_url]/list/[list]>

If you're still having trouble, please contact the list owner at:

<mailto:[list_owner_email]>

The following physical address is associated with this mailing list:

[physical_address]