Jupiter's Great Red Spot is Shrinking   
       
   May 15, 2014: Jupiter's trademark Great Red Spot -- a swirling anti-cyclonic   
   storm larger than Earth -- has shrunk to its smallest size ever measured.   
       
   According to Amy Simon of NASA's Goddard Space Flight Center in Greenbelt,   
   Maryland, recent NASA Hubble Space Telescope observations confirm the Great   
   Red Spot now is approximately 10,250 miles across, less than half the size of   
   some historical measurements. Astronomers have followed this downsizing since   
   the 1930s.   
       
   http://www.nasa.gov/sites/default/files/14-135-jupiter2_0.jpg   
       
   Images of Jupiter's Great Red Spot taken by the Hubble Space Telescope over a   
   span of 20 years show that the Great Red Spot is shrinking.   
       
   Historic observations as far back as the late 1800s gauged the storm to be as   
   large as 25,500 miles on its long axis.  NASA Voyager 1 and Voyager 2 flybys   
   of Jupiter in 1979 measured it to be 14,500 miles across. In 1995, a Hubble   
   photo showed the long axis of the spot at an estimated 13,020 miles across.   
   And in a 2009 photo, it was measured at 11,130 miles across.   
       
   Beginning in 2012, amateur observations revealed a noticeable increase in the   
   rate at which the spot is shrinking -- by 580 miles per year -- changing its   
   shape from an oval to a circle.   
       
   "In our new observations it is apparent very small eddies are feeding into the   
   storm," said Simon. "We hypothesized these may be responsible for the   
   accelerated change by altering the internal dynamics and energy of the Great   
   Red Spot."   
       
   Simon's team plans to study the motions of the small eddies and the internal   
   dynamics of the storm to determine whether these eddies can feed or sap   
   momentum entering the upwelling vortex, resulting in this yet unexplained   
   shrinkage.   
       
   NASA's Juno spacecraft is hurtling toward Jupiter now, due to reach the giant   
   planet in July 2016.  Point-blank examination by Juno's instruments will   
   undoubtedly help unravel the mystery.  Stay tuned for updates from both Hubble   
   and Juno.   
       
   Credits:   
   Production editor: Dr. Tony Phillips | Credit: Science@NASA   
       
   The Hubble Space Telescope is a project of international cooperation between   
   NASA and the European Space Agency.  Goddard Space Flight Center manages the   
   telescope. The Space Telescope Science Institute (STScI) in Baltimore conducts   
   Hubble science operations. STScI is operated for NASA by the Association of   
   Universities for Research in Astronomy, Inc., in Washington.   
       
       
   Regards,   
       
   Roger   
      
   --- D'Bridge 3.99   
    * Origin: NCS BBS - Houma, LoUiSiAna (1:3828/7)