Rosetta Comet Comes Alive   
       
   June 3, 2014:  A spacecraft from Earth is about to do something no spacecraft   
   has ever done before: orbit a comet and land on its surface.   
       
   Right now, the European Space Agency's Rosetta probe is hurtling toward Comet   
   67P/Churyumov-Gerasimenko.  The spacecraft's mission is to study the comet at   
   close-range as it transforms from a quiet nugget of ice and rock, frozen solid   
   by years spent in deep space, to a sun-warmed dynamo spewing jets of gas and   
   dust into a magnificently evolving tail.   
       
   News flash:  The metamorphosis has begun.   
       
   http://youtu.be/4x-u3v_CTcM   
       
   A new ScienceCast video previews Rosetta's mission to Comet 67P/   
   huryumov-Gerasimenko  Play it   
       
   "Comet 67P is coming alive," says Claudia Alexander, project scientist for the   
   U.S. Rosetta Project at JPL. "And it is even more active than I expected."   
       
   Launched in 2004, Rosetta has spent the past few years in hibernation as it   
   chased the comet across the Solar System. In January of 2014, with its   
   destination in sight, Rosetta woke up and turned on its cameras.  At first,   
   the comet looked like a dimensionless pinprick, inactive except for its quiet   
   motion through space.  Then, on May 4th a bright cloud appeared around the   
   nucleus.   
       
   "It's beginning to look like a real comet," says Holger Sierks of the Max   
   Planck Institute for Solar System Research in Germany where Rosetta's OSIRIS   
   science camera was built. "It is hard to believe," he says, "that only a few   
   months from now, Rosetta will be deep inside this cloud of dust and en route   
   to the origin of the comet's activity."   
       
   Spacecraft from NASA, ESA and other space agencies have flown by comets   
   before.  A whole armada of spacecraft visited Comet Halley in the mid-1980s,   
   an international event which still serves as a touchstone of comet research.   
   Other notable examples include NASA's Stardust mission, which flew through the   
   tail of Comet Wild in 2004 and returned the samples to Earth two years later;   
   and the Deep Impact spacecraft, which in 2005 dropped a projectile into Comet   
   9P/Tempel, blowing a hole in its nucleus so that researchers could look inside.   
       
   Flybys are informative, but Rosetta will do much more.   
       
   http://sci.esa.int/rosetta/54071-rosettas-target-comet-is-becoming-active/   
       
   Close-up of comet 67P/C-G on 30 April 2014.  Credit: ESA/ Rosetta/ MPS for   
   OSIRIS Team MPS/ UPD / LAM/ IAA/ SSO/ INTA/ UPM/ DASP/ IDA"A flyby is just a   
   tantalizing glimpse of a comet at one stage in its evolution," points out   
   Alexander. "Rosetta is different. It will orbit 67P for 17 months. We'll see   
   this comet evolve right before our eyes as we accompany it toward the sun and   
   back out again."   
       
   The most exciting moment of the mission will likely come in November when a   
   European-built lander descends from the spacecraft and touches down on the   
   comet's surface.  The lander's name is "Philae" after an island in the Nile,   
   the site of an obelisk that helped decipher-you guessed it-the Rosetta Stone.   
       
   Because a comet has little gravity, the lander will anchor itself with   
   harpoons. "The feet may drill into something crunchy like permafrost, or maybe   
   into something rock solid," Alexander speculates.   
       
   Once it is fastened, the lander will commence an unprecedented first-hand   
   study of a comet's nucleus while Rosetta continues to monitor developments   
   overhead.   
       
   Although Rosetta is a European mission, NASA has contributed some important   
   instruments to the spacecraft, and US scientists are just as eager as their   
   European counterparts for Rosetta to arrive.  The recent photos have helped   
   mission controllers pinpoint 67P and start a series of maneuvers that will   
   slowly bring the spacecraft in line with the comet in time for an August   
   rendezvous.   
       
   "Our target is ahead," says Alexander, "and Rosetta is chasing it down!"   
       
   Credits:   
   Author: Dr. Tony Phillips | Production editor: Dr. Tony Phillips | Credit:   
   Science@NASA   
       
   Web Links:  Rosetta -- ESA mission home page Rosetta's Target Comet is   
   Becoming Active-- ESA press release   
       
       
   Regards,   
       
   Roger   
      
   --- D'Bridge 3.99   
    * Origin: NCS BBS - Houma, LoUiSiAna (1:3828/7)