[Special Issue Research Article] On the nucleus structure and activity of comet 67P/Churyumov-Gerasimenko (Science)

Images from the OSIRIS scientific imaging system onboard Rosetta show that the nucleus of 67P/Churyumov-Gerasimenko consists of two lobes connected by a short neck. The nucleus has a bulk density less than half that of water. Activity at a distance from the Sun of >3 astronomical units is predominantly from the neck, where jets have been seen consistently. The nucleus rotates about the principal axis of momentum. The surface morphology suggests that the removal of larger volumes of material, possibly via explosive release of subsurface pressure or via creation of overhangs by sublimation, may be a major mass loss process. The shape raises the question of whether the two lobes represent a contact binary formed 4.5 billion years ago, or a single body where a gap has evolved via mass loss. Authors: Holger Sierks, Cesare Barbieri, Philippe L. Lamy, Rafael Rodrigo, Detlef Koschny, Hans Rickman, Horst Uwe Keller, Jessica Agarwal, Michael F. A`Hearn, Francesco Angrilli, Anne-Therese Auger, M. Antonella Barucci, Jean-Loup Bertaux, Ivano Bertini, Sebastien Besse, Dennis Bodewits, Claire Capanna, Gabriele Cremonese, Vania Da Deppo, Björn Davidsson, Stefano Debei, Mariolino De Cecco, Francesca Ferri, Sonia Fornasier, Marco Fulle, Robert Gaskell, Lorenza Giacomini, Olivier Groussin, Pablo Gutierrez-Marques, Pedro J. Gutiérrez, Carsten Güttler, Nick Hoekzema, Stubbe F. Hviid, Wing-Huen Ip, Laurent Jorda, Jörg Knollenberg, Gabor Kovacs, J. Rainer Kramm, Ekkehard Kührt, Michael Küppers, Fiorangela La Forgia, Luisa M. Lara, Monica Lazzarin, Cédric Leyrat, Josè J. Lopez Moreno, Sara Magrin, Simone Marchi, Francesco Marzari, Matteo Massironi, Harald Michalik, Richard Moissl, Stefano Mottola, Giampiero Naletto, Nilda Oklay, Maurizio Pajola, Marco Pertile, Frank Preusker, Lola Sabau, Frank Scholten, Colin Snodgrass, Nicolas Thomas, Cecilia Tubiana, Jean-Baptiste Vincent, Klaus-Peter Wenzel, Mirco Zaccariotto, Martin Pätzold