Comets

Six of the icy areas on the surface of the comet 67P/Churyumov-Gerasimenko found by the Rosetta space probe (Image ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)

The OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System) camera on ESA’s space probe Rosetta allowed to identify 120 icy areas on the surface of the comet 67P/Churyumov-Gerasimenko. A study of the presence of ice has just been published in the journal “Astronomy & Astrophysics”. That presence was well known but Rosetta’s observations allowed to understand the phases of transformation into gas, how much of it forms the comet’s coma and tail and what falls back to the surface.

The area of the comet 67P/Churyumov-Gerasimenko where Philae landed (Ellipse: ESA/Rosetta/Philae/CONSERT; Image: ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)

During the weekend the lander Philae resumed communications from the surface of the comet 67P/Churyumov-Gerasimenko. It’s been almost exactly seven months since Philae ran out of battery power and, because its position didn’t allow it to recharge them using its solar panels, had gone into hibernation. Now ESA is preparing new plans to try to make the most of the period in which the comet will be close enough to the Sun to provide the energy needed for Philae to work.

Picture of the comet 67P/Churyumov-Gerasimenko taken by the Rosetta space probe on May 20, 2015 that shows gas jets coming from its nucleus (Photo ESA/Rosetta/NavCam)

The journal “Astronomy and Astrophysics” will publish an article that illustrates a discovery about the atmosphere of the comet 67P/Churyumov-Gerasimenko generated by the sublimation of the ice it contains. Water, but also carbon dioxide, are turned into steam but thanks to the instrument Alice of the space probe Rosetta it was possible to discover that these molecules get broken and that this happens in two stages.

Photo of the balancing rocks taken by the Rosetta space probe's OSIRIS camera on September 16, 2014 (Image ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)

The scientists of the Rosetta space probe’s OSIRIS camera’s team discovered a curious rock formation in the region called Aker of the comet 67P/Churyumov-Gerasimenko. They look like the balancing rocks existing in various places on Earth and precisely these are three rocks that seem to have very little contact with the comet’s surface.

Picture of the comet 67P/Churyumov-Gerasimenko taken on March 12, 2015 at 5.13 UTC. No jets are coming from the bottom area (Image ESA/Rosetta/MPS for OSIRIS Team MPS/UPD/LAM/IAA/SSO/INTA/UPM/DASP/IDA)

ESA’s space probe Rosetta identified new jets of gas and dust emerge from the comet 67P/Churyumov-Gerasimenko. The images were taken using the OSIRIS camera on March 12, 2015 and were presented last week during EGU2015 (European Geosciences Union General Assembly 2015) in Vienna. The activity on the comet keeps on increasing but it took some luck to detect new jets.