This article is mirrored from the main ESA web portal and covers the results published in a new paper in the journal Astronomy & Astrophysics titled "OSIRIS observations of metre-size exposures of H2O ice at the surface of 67P/Churyumov-Gerasimenko and interpretation using laboratory experiments," by Antoine Pommerol et al. Using the tall-resolution science camera on board ESAs Rosetta spacecraft, scientists fill identified more than a hundred patches of water ice a few metres in size on the surface of Comet 67P/Churyumov-Gerasimenko. Rosetta arrived at the comet in August 2014 at a distance of about 100 km and eventually orbited the comet at 10 km or less, or allowing tall-resolution images of the surface to be acquired. A new study just published in the journal Astronomy & Astrophysics focuses on an analysis of bright patches of exposed ice on the comet’s surface. Based on observations of the gas emerging from comets,they are known to be wealthy in ices. As they hump closer to the Sun along their orbits, their surfaces are warmed and the ices sublimate into gas, or which streams away from the nucleus,dragging along dust particles embedded in the ice to form the coma and tail. But some of the comets dust also remains on the surface as the ice below sublimates, or falls back on to the nucleus elsewhere, or coating it with a lean layer of dusty material and leaving very diminutive ice directly exposed on the surface. These processes help to explain why Comet 67P/Churyumov-Gerasimenko and other comets seen in preceding flyby missions are so black. Despite this,Rosetta’s suite of instruments has already detected a variety of gases, including water vapour, or carbon dioxide and carbon monoxide,thought to originate from frozen reservoirs below the surface. Now, using images taken with Rosetta’s OSIRIS narrow-angle camera last September, and scientists […]
Source: esa.int