The Rosetta spacecraft is closing in on a rendezvous with its target, the comet 67P/Churyumov-Gerasimenko. The vehicle is scheduled to meet up with the comet on Aug. 6.
As Rosetta approaches the comet, the vehicle is starting to produce more detailed images of the icy nucleus, as well as gather more data about the object.
Astronomers have now seen structure on the comet for the first time. What they are seeing appears to show the comet either consists of three parts, or could feature a large hole in its nucleus.
"From what we can discern in these early images, 67P is an irregularly looking body," Holger Sierks, OSIRIS principal investigator for the Max Planck Institute for Solar System Research (MPS) in Germany, said. The scientific imaging system OSIRIS was built by a consortium led by the Max Planck Institute for Solar System Research.
A series of new images clearly showing the unusual structure were taken from 23,000 miles away from the frozen body. In the images, the body of the comet only fills 30 pixels, leaving exact identification of the structure of the comet still in question. This is the last leg of the spacecraft's 10-year voyage to comet 67P/Churyumov-Gerasimenko.
"[O]n 6 August, we will have covered 99% of the remaining distance to the comet, rendezvousing with the comet at a distance of 100 km. Eventually, the plan is to come to within just [6.25 miles] altitude, although there are many unknowns including the comet's mass, gravitational field, and activity which need to be determined and understood before Rosetta can move in that close," European Space Agency officials wrote on the Rosetta blog.
Five comets so far have been visited by robotic spacecraft. Each of the icy bodies was found to have an irregular shape, far from being perfect spheres. Larger bodies, measuring hundreds of miles across, have enough gravity to form into spheres. Smaller objects, like asteroids and comets, do not have enough gravity to coalesce into round forms. One comet, 103P/Hartley, was found to be shaped like a duck ball bowling pin, with one fat side, and one thinner end.
Rosetta was launched on March 2, 2004. Attached to the vehicle is the Philae lander, which will soon become the first man-made object to ever come in contact with a comet, when it touches down on the surface of 67P/Churyumov-Gerasimenko. Rosetta is a European Space Agency mission with contributions from its member states and NASA.
The European Space Agency is sponsoring a photo contest to celebrate the arrival of Rosetta at the comet. The contest will feature photographs of arrivals and departures. The agency is encouraging entrants to have tie-ins between their photo and the Rosetta mission. For instance, water is a large component of comets, so photos of arrivals and departures from waterways could be good examples. The grand prize is a trip to Rosetta mission control in Germany to witness the landing of Philae in November. Entries are accepted until Aug. 6.
