Two articles published in the journal “Monthly Notices of the Royal Astronomical Society” describe two researches on comet 67P/Churyumov-Gerasimenko based on data collected by ESA’s Rosetta space probe. In an article, a team led by Jürgen Blum of the Technische Universität Braunschweig, Germany, used the data collected to find out how the comet formed. In the other article, a team led by Jessica Agarwal of the Max Planck Institute for Solar System Research in Göttingen, Germany, described a plume on the surface of the comet that could have been generated by pressurized underground gas or by the crystallization of amorphous water ice.