The unusual shape of comet 67P/Churyumov-Gerasimenko, as recorded by the Rosetta mission, has led to much speculation about its origins. A simulation published in March 2018 in Nature Astronomy suggests that the comet could have formed when two comets collided, and furthermore that such a collision even at quite high speeds would have left the constituent parts largely unaltered (no large rise in temperatures or pressures). This is important because it means that whenever Churyumov-Gerasimenko actually took its current shape, we can still draw conclusions about primordial material from the origins of the solar system using Rosetta results.
A recent paper suggests that Pluto may be compositionally similar to comet 67P, and so have been formed from about one billion similar comets. The paper, by authors at the Southwest Research Institute in the USA, combines data from ESA’s Rosetta mission with data from NASA’s New Horizons mission. In particular, the authors found that nitrogen concentrations were similar for a region on Pluto and for comet 67P. A press release summarises the findings of the paper “Primordial N2 provides a cosmochemical explanation for the existence of Sputnik Planitia, Pluto” published in the journal Icarus (no open access).
Scientist Raphael Marschall from the MiARD project recently gave a talk to the Bern section of the ‘Astronomy on Tap’ movement that seeks to provide popular science talks with an astronomy theme to the general public in an informal setting. A video of his talk can be seen here, in which he summarises the reasons for studying comets, and his own research using results from the ROSETTA mission.