Overview of the Geomorphology of the Nucleus of Comet 67P/Churyumov-Gerasimenko from OSIRIS Observations

Wednesday, 17 December 2014: 1:40 PM
Olivier Groussin1, Nicolas Thomas2, Holger Sierks3, Cesare Barbieri4, Philippe L Lamy1, Hans Rickman5, Rafael Rodrigo6 and Detlef Koschny7, (1)Laboratoire d'Astrophysique de Marseille, Marseille, France, (2)University of Bern, Bern, Switzerland, (3)Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany, (4)University of Padua, Padua, Italy, (5)Uppsala University, Department of Physics and Astronomy, Uppsala, Sweden, (6)IAA-CSIC, Granada, Spain, (7)European Space Research and Technology Centre, Noordwijk, Netherlands
Because of the very peculiar conditions at the surface of cometary nuclei with very low gravity, outgassing, presence of ices and dust, their geomorphology is particularly complex. The presence of hummocky terrains (e.g., pits, hills, ridges, ...) and smooth terrains (e.g., mesas, …) and their spatial distribution over the surface contain very valuable information to understand how comets work and to which extend they may still contain pristine materials on or close to their surface. Since July 2014, the Rosetta spacecraft has taken numerous high spatial resolution images (meter scale) of the surface of the nucleus of comet 67P/Churyumov-Gerasimenko with the OSIRIS cameras NAC (Narrow Angle Camera) and WAC (Wide Angle Camera). In this paper, we will present an overview of the geomorphologic features observed on this comet nucleus, including the cartography of the main features, and try to propose a scenario for the chronology of their formation and evolution.