The first key haul of research from the European Space Agency’s Rosetta mission, issued in seven papers in Science on 22 January, discloses a gorgeous and diverse landscape on comet 67P/Churyumov–Gerasimenko, the utmost studied comet in history of human kind. The finest images — several of which had been offered first in December at a meeting of the American Geophysical Union — are also pictured below.
Charting gravity of comet 67P/Churyumov–Gerasimenko
By means of data from the Optical, Spectroscopic, and Infrared Remote Imaging System-OSIRIS and also from the Radio Science Investigation tool, the Rosetta mission group analyzed and calculated the gravitational field of comet 67P/Churyumov–Gerasimenko. The gravitational potential (as pictured below) also involves an attraction produced by the comet’s rotation. The subsequent force is max on top of the lobes, but it is nearly six times weaker in the neck area, where dust can escape more effortlessly. The group also used the data to compute the comet’s density, finding that the body is quite fluffy and absorbent — with a density of nearly half that of water, providing hints as to its structure and strength.
Clues to the origin of comet 67P/Churyumov–Gerasimenko
Comprehensive images, at their finest with a resolution of 15 centimetres per pixel, display arrangements that could provide clues at the comet’s history. Three-metre-wide landscapes nicknamed “goosebumps”, imaged here running down the inside of a ditch in the Seth region, are discovered all over the comet’s surface. Holger Sierks of the Max Planck Institute for Solar System Research in Göttingen, Germany, who is also principal investigator on the OSIRIS camera device, states that the pebble-like forms could hint at the scale on which particles of dust and ice first clunked together in the early age of Solar System. He says “The hypothesis is these might be the building blocks of comets,”
The neck riddle of comet 67P/Churyumov–Gerasimenko
Gathered data from numerous instruments indicate that the comet’s neck is the source of maximum of its flowing gas and dust. To comprehend why the neck section is so lively, the Rosetta group observed at how much thermal energy touches the surface per 12.4-hour rotation (left side) and per 6.5-year solar orbit (right side). The neck gets less energy from the Sun than the rest of the comet since it is covered, but they discovered that a suntrap influence from radiation bouncing among opposite cliff walls goes some way towards compensating for that. Further probable explanations for the region's high activity comprise its low gravitational pull, which means that minute force is required to blow dust away, and that the section might have a dissimilar structure than other regions, or have more prepared entrance to water under the surface. The group has still to response whether the neck represents a joint between two comets or has been sliced out of a single comet by destruction. Indication of changes between the two lobes would specify the former, but so far the two lobes appear to have very alike structures, says Sierks.