Geologic mapping of the Comet 67P/Churyumov-Gerasimenko's Northern Hemisphere

Lorenza Giacomini (1) , Matteo Massironi (1) , Mohamed R. El-Maarry (2) , Luca Penasa (3) , Maurizio Pajola (4) , Nicholas Thomas (2) , Stephen C. Lowry (5) , Cesare Barbieri (6) , Gabriele Cremonese (7) , Francesca Ferri (3) , Giampiero Naletto (8) , Ivano Bertini (3) , Fiorangela La Forgia (6) , Mario Lazzarin (6) , Francesco Marzari (6) , Holger Sierks (9) , Philippe L. Lamy (10) , Rafael Rodrigo (11, 12) , Hans Rickman (13, 14) , Detlef Koschny (15) , Horst U. Keller (16) , Jessica Agarwal (9) , Michael F. A'Hearn (17) , Anne-Thérèse Auger (10) , Maria Antonietta Barucci (18) , Jean-Loup Bertaux (19) , Sebastien Besse (20) , Dennis Bodewits (17) , Vania da Deppo (21) , Björn Davidsson (14) , Mariolino de Cecco (22) , Stefano Debei (23) , Sonia Fornasier (18) , Marco Fulle (24) , Olivier Groussin (10) , Pedro J. Gutiérrez (25) , Carsten Güttler (9) , Stubbe F. Hviid (26) , Wing-Huen Ip (27) , Laurent Jorda (10) , Jörg Knollenberg (26) , Gabor Kovacs (9) , J.-Rainer Kramm (9) , Ekkehard Kührt (26) , Michael Küppers (28) , Luisa M. Lara (25) , Jose J. Lopez Moreno (25) , Sara Magrin (6) , Harald Michalik (29) , Nilda Oklay (9) , Antoine Pommerol (2) , Frank Preusker (26) , Frank Scholten (26) , Cecilia Tubiana (9) , Jean-Baptiste Vincent (9)

1 Dipartimento di Geoscienze [Padova]
2 Physikalisches Institut [Bern]
3 CISAS - Centro di Ateneo di Studi e Attività Spaziali “Giuseppe Colombo”
4 ARC - NASA Ames Research Center
5 School of Physical Sciences [Canterbury]
6 Dipartimento di Fisica e Astronomia "Galileo Galilei"
7 OAPD - INAF - Osservatorio Astronomico di Padova
8 DEI - Department of Information Engineering [Padova]
9 MPS - Max-Planck-Institut für Sonnensystemforschung
10 LAM - Laboratoire d'Astrophysique de Marseille
11 CAB - Centro de Astrobiologia [Madrid]
12 ISSI - International Space Science Institute [Bern]
13 CBK - Space Research Centre of Polish Academy of Sciences
14 Department of Physics and Astronomy [Uppsala]
15 ESTEC - European Space Research and Technology Centre
16 IGEP - Institut für Geophysik und Extraterrestrische Physik [Braunschweig]
17 Department of Astronomy [College Park]
18 LESIA - Laboratoire d'études spatiales et d'instrumentation en astrophysique
19 PLANETO - LATMOS
20 RSSD - Research and Scientific Support Department, ESTEC
21 IFN - CNR Institute for Photonics and Nanotechnologies
22 University of Trento [Trento]
23 Department of Industrial Engineering [Padova]
24 OAT - INAF - Osservatorio Astronomico di Trieste
25 IAA - Instituto de Astrofísica de Andalucía
26 DLR Institut für Planetenforschung
27 Institute of Space Science [Taiwan]
28 Operations Department (ESAC)
29 IDA - Institute of Computer and Network Engineering [Braunschweig]

OSIRIS, the Scientific Imaging System onboard the Rosetta mission, has been acquiring images of the nucleus of the comet 67P/Churyumov-Gerasimenko since August 2014 with a resolution that allows a detailed analysis of its surface. Indeed, data reveal a complex surface morphology that is likely the expression of different processes that occurred at different times on the cometary nucleus. In order to characterize these different morphologies and better understand their distribution, we performed a geologic mapping of comet's 67P northern hemisphere in which features have been distinguished based on their morphological, textural and stratigraphic characteristics. For this purpose we used NAC images acquired on August and September 2014 with a spatial scale ranging from 1.2 to 2.4 m/pixel. Several different geologic units have been identified on the basis of their different surface textures, granulometry, and morphology. Some of these units are distinctive and localised, whereas others are more common and distributed all over the northern hemisphere. Moreover, different types of linear features have been distinguished on the basis of their morphology. Some of these lineaments have never been observed before on a comet and can offer important clues on the internal structures of the nucleus itself. The geologic mapping results presented here will allow us to better understand the processes that affected the nucleus’ surface and thus the origin and evolutionary history of comet 67P/Churyumov-Gerasimenko.

Keywords: 67P/ Churyumov-Gerasimenko

Domains: Earth and Planetary Astrophysics [astro-ph.EP]; Solar and Stellar Astrophysics [astro-ph.SR]

Lorenza Giacomini, Matteo Massironi, Mohamed R. El-Maarry, Luca Penasa, Maurizio Pajola, et al.. Geologic mapping of the Comet 67P/Churyumov-Gerasimenko's Northern Hemisphere. Monthly Notices of the Royal Astronomical Society, 2016, 462 (Suppl. 1), pp.S352-S367. ⟨10.1093/mnras/stw2848⟩. ⟨insu-01393316⟩