New Views of the Rosetta Comet
 
July 24, 2014: As the European Space Agency's Rosetta probe approaches
Comet 67P/Churyumov-Gerasimenko (67P) for an August rendezvous, the comet's
core is coming into sharper focus. Today, ESA released a new set of images
and a striking 3D model of 67P's nucleus.
 
http://tinyurl.com/q9qsdx4
 
Images of comet 67P/Churyumov-Gerasimenko taken on July 14, 2014, by the
OSIRIS imaging system aboard the European Space Agency's Rosetta spacecraft
have allowed scientists to create this three-dimensional shape model of the
nucleus. Image Credit:  ESA/Rosetta/MPS for OSIRIS
Team/MPS/UPD/LAM/IAA/SSO/INTA/UPM Full image and caption
 
The resolution of the latest images taken by the spacecraft's OSIRIS
imaging system on July 20th is 330 feet (100 meters) per pixel.  At that
resolution, 67P appears to consist of two parts: a smaller head connected
to a larger body. The connecting region, the neck, is proving to be
especially intriguing.
 
"The only thing we know for sure at this point is that this neck
region appears brighter compared to the head and body of the nucleus,"
says OSIRIS Principal Investigator Holger Sierks from the Max Planck
Institute for Solar System Research in Germany. This collar-like appearance
could be caused by differences in material or grain size, or could be a
topographical effect--no one knows.
 
The appearance of 67P reminds mission scientists of comet 103P/Hartley,
which was visited in a flyby by NASA's EPOXI mission in 2010. While
Hartley's ends show a rather rough surface, its middle is much smoother.
Scientists believe this waist to be a "gravitational low."
Because it contains the body's center of mass, material kicked up by, say,
meteoroid impacts, that cannot leave the comet's gravitational field is
most likely to be re-deposited there.
 
http://tinyurl.com/nr6bzh4
 
Comet 67P/Churyumov-Gerasimenko was imaged by the European Space Agency's
Rosetta spacecraft on July 20, 2014, from a distance of approximately 3,400
miles (5,500 kilometers). These three images were taken two hours apart.
Image Credit:  ESA/Rosetta/MPS for OSIRIS Team/MPS/UPD/LAM/IAA/SSO/INTA/UPM
Full image and caption
 
Whether this also holds true for 67P's neck region is still unclear.
Another explanation for the high reflectivity could be a different surface
composition. In coming weeks, the OSIRIS team hopes to analyze the spectral
data of this region obtained with the help of the imaging system's filters.
These can select several wavelength regions from the reflected light,
allowing scientists to identify the fingerprints of certain materials and
compositional features.
 
Rosetta will be the first mission in history to rendezvous with a comet,
escort it as it orbits the sun, and deploy a lander to its surface. ESA
says the next high-resolution OSIRIS image will be published on July 31st. 
Stay tuned!
 
Credits:
Author: Dr. Tony Phillips | Production editor: Dr. Tony Phillips | Credit:
Science{at}NASA
 
Credits:
Rosetta's Philae lander is provided by a consortium led by the German
Aerospace Center, Cologne; Max Planck Institute for Solar System Research,
Gottingen; French National Space Agency, Paris; and the Italian Space
Agency, Rome. The Jet Propulsion Laboratory, a division of the California
Institute of Technology, Pasadena, manages the U.S. participation in the
Rosetta mission for NASA's Science Mission Directorate in Washington.
Rosetta carries three NASA instruments in its 21-instrument payload.
 
Web Links
European Space Agency home page
 
Rosetta -- from the ESA
 
Rosetta -- from NASA
 
NASA Instruments on Rosetta
 
Rosetta Comet Comes Alive -- from Science{at}NASA
 
 
Regards,
 
Roger

--- D'Bridge 3.99