Computer model of Comet 67P/C-G based on images acquired July 14-24. ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
Just 10 days away from arriving at its destination, the European Space Agency's Rosetta spacecraft has already gotten its first good looks at comet 67P/Churyumov-Gerasimenko, revealing a surprising double-lobed nucleus (that was immediately likened to a bathtub toy duck.)
Now, computer modeling reveals more details of the comet's true shape, making it appear somewhat less rubber-duckish and a bit more like... well, I'm not really sure what. Perhaps a wad of chewing gum.
Still, at nearly 2.5 miles across, that's one big wad of gum!
The three-dimensional rendering and animation above was created from data acquired by Rosetta's OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System) narrow-angle camera from July 14-24, as the spacecraft was closing in on the comet from distances of 12,000 km (7,456 miles) to less than 3,500 km (2,174 miles).
While it might appear that surface features are visible, it's still not yet known if all the bumps and dark spots really are actual landforms or just the result of image artifacts. But Rosetta has since gotten even closer, and better, more detailed images are coming in by the day, gradually filling in missing information.
Below are images of the comet acquired by OSIRIS on July 20, 2014, from a distance of about 5,500 km (3,417 miles)… about the distance between New York and London. In these views the comet's terrain becomes quite a bit clearer, revealing additional bumps and what seems to be a crater on the comet's "head."
OSIRIS narrow-angle camera images of comet 67P/C-G from July 20. ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA
67P has a rotation period of 12.4 hours. The individual images were taken two hours apart.
Of particular interest to scientists is the brighter band running along the connection between the two segments of the comet (i.e., the duck's neck.) This could be the result of a reflective, icy composition exposed by erosion processes, or perhaps a region of smaller, more finely-grained material. Whatever it is it could provide more insight on how comet 67P/C-G formed and evolved to become the binary shape Rosetta is showing us today.
Also, with the Philae probe scheduled to attempt the first-ever soft landing on a comet in November, knowing what 67P is made of and what its surface is really like will be of utmost importance.
More OSIRIS images of 67P will be released on July 31, when Rosetta will be just a week away from becoming the first spacecraft ever to orbit a comet. For the latest images of comet 67P/C-G acquired on July 25-27 with Rosetta's navigational camera (which uses a much wider angle than OSIRIS) visit the Rosetta blog site here.