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

¹ German Aerospace Center (DLR), Institute of Planetary Research, 12489 Berlin, Germany
e-mail: Frank.Preusker@dlr.de
² NASA Ames Research Center, Moffett Field, CA 94035, USA
³ Department of Physics and Astronomy, Uppsala University, Box 516, 75120 Uppsala, Sweden
⁴ University of Maryland, Department of Astronomy, College Park, MD 20742-2421, USA
⁵ Max Planck Institute for Solar System Research, Justus-von-Liebig-Weg 3, 37077 Göttingen, Germany
⁶ University of Padova, Department of Physics and Astronomy, Vicolo dell’Osservatorio 3, 35122 Padova, Italy
⁷ LESIA, Observatoire de Paris, PSL Research University, CNRS, Univ. Paris Diderot, Sorbonne Paris Cité, UPMC Univ. Paris 06, Sorbonne Universités, 5 place Jules Janssen, 92195 Meudon, France
⁸ LATMOS, CNRS/UVSQ/IPSL, 11 boulevard d’Alembert, 78280 Guyancourt, France
⁹ Center of Studies and Activities for Space (CISAS) “G. Colombo”, University of Padova, via Venezia 15, 35131 Padova, Italy
¹⁰ INAF–Osservatorio Astronomico di Padova, Vicolo dell’Osservatorio 5, 35122 Padova, Italy
¹¹ CNR – IFN UOS Padova LUXOR, via Trasea 7, 35131 Padova, Italy
¹² Department of Industrial Engineering, University of Padova, via Venezia 1, 35131 Padova, Italy
¹³ University of Trento, Faculty of Engineering, via Mesiano 77, 38121 Trento, Italy
¹⁴ INAF–Osservatorio Astronomico di Trieste, via Tiepolo 11, 34143 Trieste, Italy
¹⁵ Aix-Marseille Université, CNRS, LAM (Laboratoire d’Astrophysique de Marseille), UMR 7326, 38 rue Frédéric Joliot-Curie, 13388 Marseille, France
¹⁶ Instituto de Astrofísica de Andalucía (CSIC), c/ Glorieta de la Astronomìa s/n, 18008 Granada, Spain
¹⁷ Graduate Institute of Astronomy, National Central University, 300 Chung-Da Rd, Chung-Li 32054, Taiwan
¹⁸ Space Science Institute, Macau University of Science and Technology, Avenida Wai Long, Taipa, Macau, PR China
¹⁹ Institut für Geophysik und extraterrestrische Physik (IGEP), Technische Universität 31 Braunschweig, Mendelssohnstr. 3, 38106 Braunschweig, Germany
²⁰ Scientific Support Office, European Space Research and Technology Centre/ESA, Keplerlaan 1, Postbus 299, 2201 AZ Noordwijk ZH, The Netherlands
²¹ Operations Department, European Space Astronomy Centre/ESA, PO Box 78, 28691 Villanueva de la Cañada, Madrid, Spain
²² Department of Information Engineering, University of Padova, via Gradenigo 6/B, 35131 Padova, Italy
²³ PAS Space Research Center, Bartycka 18A, 00716 Warszawa, Poland
²⁴ Centro de Astrobiología, CSIC-INTA, Torrejón de Ardoz, 28850 Madrid, Spain
²⁵ International Space Science Institute, Hallerstrasse 6, 3012 Bern, Switzerland
²⁶ Physikalisches Institut der Universität Bern, Sidlerstr. 5, 3012 Bern, Switzerland
²⁷ Center for Space and Habitability, University of Bern, 3012 Bern, Switzerland

Received: 18 August 2017
Accepted: 23 September 2017

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 km³ ± 0.02 km³ for the volume and 537.8 kg/m³ ± 0.7 kg/m³ for the mean density assuming a mass value of 9.982 × 10¹² kg.