The global meter-level shape model of comet 67P/Churyumov-Gerasimenko

Abstract

We performed a stereo-photogrammetric (SPG) analysis of more than 1500 Rosetta/OSIRIS NAC images of comet 67P/Churyumov-Gerasimenko (67P). The images with pixel scales in the range 0.2-3.0 m/pixel were acquired between August 2014 and February 2016. We finally derived a global high-resolution 3D description of 67P's surface, the SPG SHAP7 shape model. It consists of about 44 million facets (1-1.5 m horizontal sampling) and a typical vertical accuracy at the decimeter scale. Although some images were taken after perihelion, the SPG SHAP7 shape model can be considered a pre-periheliondescription and replaces the previous SPG SHAP4S shape model. From the new shape model, some measures for 67P with very low 3σ uncertainties can be retrieved: 18.56 km<SUP>3</SUP> ± 0.02 km<SUP>3</SUP> for the volume and 537.8 kg/m<SUP>3</SUP> ± 0.7 kg/m<SUP>3</SUP> for the mean density assuming a mass value of 9.982 × 10<SUP>12</SUP> kg.