Astronomers have found that the nucleus of the comet Churyumov — Gerasimenko could have formed when moving the direct collision of two cometesimals, between which is formed a jumper. However, the proportion of the kernel was robust enough to not disintegrate upon impact, helped ice and organic material. Article published in the journal Proceedings of the National Academy of Sciences.
Short-period comet 67P/Churyumov — Gerasimenko is the main objective for the interplanetary station “Rosetta”, who examined her for two years and collected a huge amount of data about the nucleus and coma of the comet, and also about the changes in her behavior during the approach the Sun. In November 2014, the station for the first time in the history landed on the surface of the comet’s nucleus module that managed to collect scientific data to loss contact with him. The scientific program of the station ended 30 September 2016 it is planned hard landing on the comet nucleus.
During the work of the “Rosetta” received a huge number of images of the surface of the comet’s nucleus, characterized by high granularity, which allowed scientists to learn more about its origin and evolution. The core consists of two lobes of different sizes, connected by a bridge, its total volume is estimated at 18.56 cubic kilometers. There are two versions of the formation of such shapes of the nucleus, the first assumes that the creation of a jumper responsible strong erosion in this area, the second is that the nucleus formed in the collision of two different cometesimals. The latest version has evidence in its favor and is considered the most likely.
A team of astronomers led Marco Francesca (Marco Franceschia) from the University of Padova has published the results of mapping three-dimensional models for the formation of the comet Churyumov — Gerasimenko as a result of collision of two bodies with observations of Rosetta. Scientists came to the conclusion that in the past two ellipsoid was cometesimals, with an approximate volume of 34 and 15 cubic kilometers, experienced moving direct confrontation, which led to large-scale deformation in brittle-plastic regime, which formed folds in a layered structure of the lobes, and the layers are not erased. Observed on the surface of the nucleus multiple long (of the order of several tens of meters) of cracks that could not be formed by thermal processes, and evidence of mass-loss fractions (up to 60 percent of the original volume), with homogeneous internal density of the comet, also confirm the idea of deformation the share in the result of a collision, without seal substances within them.