Gigantic Hurricane Spotted on Saturn   
       
   April 29, 2013: NASA's Cassini spacecraft has provided scientists the first   
   close-up, visible-light views of a behemoth hurricane swirling around Saturn's   
   north pole.   
       
   In high-resolution pictures and video, scientists see the hurricane's eye is   
   about 1,250 miles (2,000 kilometers) wide, 20 times larger than the average   
   hurricane eye on Earth. Thin, bright clouds at the outer edge of the hurricane   
   are traveling 330 mph(150 meters per second). The hurricane swirls inside a   
   large, mysterious, six-sided weather pattern known as the hexagon.   
       
   http://tinyurl.com/d4h9uyl   
       
   A narrated video shows a hurricane-like storm seen at Saturn's north pole by   
   NASA's Cassini spacecraft. Play it   
      
   "We did a double take when we saw this vortex because it looks so much like a   
   hurricane on Earth," said Andrew Ingersoll, a Cassini imaging team member at   
   the California Institute of Technology in Pasadena. "But there it is at   
   Saturn, on a much larger scale, and it is somehow getting by on the small   
   amounts of water vapor in Saturn's hydrogen atmosphere."   
       
   Scientists will be studying the hurricane to gain insight into hurricanes on   
   Earth, which feed off warm ocean water. Although there is no body of water   
   close to these clouds high in Saturn's atmosphere, learning how these   
   Saturnian storms use water vapor could tell scientists more about how   
   terrestrial hurricanes are generated and sustained.   
       
   Both a terrestrial hurricane and Saturn's north polar vortex have a central   
   eye with no clouds or very low clouds. Other similar features include high   
   clouds forming an eye wall, other high clouds spiraling around the eye, and a   
   counter-clockwise spin in the northern hemisphere.   
       
   A major difference between the hurricanes is that the one on Saturn is much   
   bigger than its counterparts on Earth and spins surprisingly fast. At Saturn,   
   the wind in the eye wall blows more than four times faster than    
   urricane-force winds on Earth. Unlike terrestrial hurricanes, which tend to   
   move, the Saturnian hurricane is locked onto the planet's north pole. On   
   Earth, hurricanes tend to drift northward because of the forces acting on the   
   fast swirls of wind as the planet rotates. The one on Saturn does not drift   
   and is already as far north as it can be.   
       
   "The polar hurricane has nowhere else to go, and that's likely why it's stuck   
   at the pole," said Kunio Sayanagi, a Cassini imaging team associate at Hampton   
   University in Hampton, Va.   
       
   http://tinyurl.com/bwgdqxt   
       
   This spectacular, vertigo inducing, false-color image from NASA's Cassini   
   mission highlights the storms at Saturn's north pole. Image credit:   
   NASA/JPL-Caltech/SSI Scientists believe the massive storm has been churning   
   for years. When Cassini arrived in the Saturn system in 2004, Saturn's north   
   pole was dark because the planet was in the middle of its north polar winter.   
   During that time, the Cassini spacecraft's composite infrared spectrometer and   
   visual and infrared mapping spectrometer detected a great vortex, but a   
   visible-light view had to wait for the passing of the equinox in August 2009.   
   Only then did sunlight begin flooding Saturn's northern hemisphere. The view   
   required a change in the angle of Cassini's orbits around Saturn so the   
   spacecraft could see the poles.   
       
   "Such a stunning and mesmerizing view of the hurricane-like storm at the north   
   pole is only possible because Cassini is on a sportier course, with orbits   
   tilted to loop the spacecraft above and below Saturn's equatorial plane," said   
   Scott Edgington, Cassini deputy project scientist at NASA's Jet Propulsion   
   Laboratory in Pasadena, Calif. "You cannot see the polar regions very well   
   from an equatorial orbit. Observing the planet from different vantage points   
   reveals more about the cloud layers that cover the entirety of the planet."   
       
   Cassini changes its orbital inclination for such an observing campaign only   
   once every few years. Because the spacecraft uses flybys of Saturn's moon   
   Titan to change the angle of its orbit, the inclined trajectories require   
   attentive oversight from navigators. The path requires careful planning years   
   in advance and sticking very precisely to the planned itinerary to ensure   
   enough propellant is available for the spacecraft to reach future planned   
   orbits and encounters.   
       
   For more information about Cassini and its mission, visit: http:   
   /www.nasa.gov/cassini and http://saturn.jpl.nasa.gov .   
       
   Credits:   
       
    Production editor: Dr. Tony Phillips | Credit: Science@NASA   
       
   More information:   
       
   Cassini  -- mission home page   
       
   The Cassini-Huygens mission is a cooperative project of NASA, the European   
   Space Agency and the Italian Space Agency. JPL, a division of the California   
   Institute of Technology, Pasadena, manages the Cassini-Huygens mission for   
   NASA's Science Mission Directorate in Washington. The Cassini orbiter and its   
   two onboard cameras were designed, developed and assembled at JPL. The imaging   
   team consists of scientists from the United States, the United Kingdom, France   
   and Germany. The imaging operations center is based at the Space Science   
   Institute in Boulder, Colo   
       
       
   Regards,   
       
   Roger   
      
   --- D'Bridge 3.92   
    * Origin: NCS BBS - Houma, LoUiSiAna (1:3828/7)