I should have known that as soon as I said something about NASA, they would   
   send me an article, so here it is:   
       
   Hubble Sees an Asteroid with Six Comet-like Tails   
       
   Nov. 7, 2013:  Astronomers viewing our solar system's asteroid belt with   
   NASA's Hubble Space Telescope have seen for the first time an asteroid with   
   six comet-like tails of dust. Designated P/2013 P5, the asteroid resembles a   
   rotating lawn sprinkler.   
       
   "We were literally dumbfounded when we saw it," said lead investigator David   
   Jewitt of the University of California at Los Angeles. "Even more amazing, its   
   tail structures change dramatically in just 13 days as it belches out dust.   
   That also caught us by surprise. It's hard to believe we're looking at an   
   asteroid."   
       
   http://tinyurl.com/k9uhklf   
       
   This NASA Hubble Space Telescope set of images reveals a never-before-seen set   
   of six comet-like tails radiating from a body in the asteroid belt, designated   
   P/2013 P5.   
       
   Jewitt leads a team whose research paper appears online in the Nov. 7 issue of   
   the Astrophysical Journal Letters.   
       
   P/2013 P5 has been ejecting dust periodically for at least five months.   
   Astronomers believe it is possible the asteroid's rotation rate increased to   
   the point where its surface started flying apart. They do not believe the   
   tails are the result of an impact with another asteroid because they have not   
   seen a large quantity of dust blasted into space all at once.   
       
   Scientists using the Pan-STARRS survey telescope in Hawaii announced their   
   discovery of the asteroid Aug. 27. P/2013 P5 appeared as an unusually   
   fuzzy-looking object. The multiple tails were discovered when Hubble was used   
   to take a more detailed image Sept. 10.   
       
   When Hubble looked at the asteroid again Sept. 23, its appearance had totally   
   changed. It looked as if the entire structure had swung around.   
       
   "We were completely knocked out," Jewitt said.   
       
   Careful modeling by team member Jessica Agarwal of the Max Planck Institute   
   for Solar System Research in Lindau, Germany, showed that the tails could have   
   been formed by a series of impulsive dust-ejection events. She calculated that   
   dust-ejection events occurred April 15, July 18, July 24, Aug. 8, Aug. 26 and   
   Sept. 4.  Radiation pressure from the sun stretched the dust into streamers.   
       
   Radiation pressure could have spun P/2013 P5 up. Jewitt said the spin rate   
   could have increased enough that the asteroid's weak gravity no longer could   
   hold it together. If that happened, dust could slide toward the asteroid's   
   equator, shatter and fall off, and drift into space to make a tail. So far,   
   only about 100 to 1,000 tons of dust, a small fraction of the P/2013 P5's main   
   mass, has been lost. The asteroid's nucleus, which measures 1,400 feet wide,   
   is thousands of times more massive than the observed amount of ejected dust.   
       
   Astronomers will continue observing P/2013 P5 to see whether the dust leaves   
   the asteroid in the equatorial plane. If it does, this would be strong   
   evidence for a rotational breakup. Jewitt's interpretation implies that   
   rotational breakup must be a common phenomenon in the asteroid belt. It might   
   even be the main way small asteroids die.   
       
   "In astronomy, where you find one, you eventually find a whole bunch more,"   
   Jewitt said. "This is just an amazing object to us, and almost certainly the   
   first of many more to come."   
       
   Credits:   
       
   Production editor: Dr. Tony Phillips | Credit: Science@NASA   
       
   More information:   
       
   Jewitt said it appears P/2013 P5 is a fragment of a larger asteroid that broke   
   apart in a collision roughly 200 million years ago. There are many collision   
   fragments in orbits similar to P/2013 P5's. Meteorites from these bodies show   
   evidence of having been heated to as much as 1,500 degrees Fahrenheit. This   
   means the asteroid likely is composed of metamorphic rocks and does not hold   
   any ice as a comet does.   
       
       
   Regards,   
       
   Roger   
      
   --- D'Bridge 3.96   
    * Origin: NCS BBS - Houma, LoUiSiAna (1:3828/7)