Regional surface morphology of comet 67P/Churyumov-Gerasimenko from Rosetta/OSIRIS images
El-Maarry, Mohamed Ramy and Thomas, N. and Giacomini, L. and Massironi, M. and Pajola, M. and Marschall, R. and Gracia-Berná, A. and Sierks, H. and Barbieri, C. and Lamy, P.L. and Rodrigo, R. and Rickman, H. and Koschny, D. and Keller, H.U. and Agarwal, J. and A’Hearn, M.F. and Auger, A.-T. and Barucci, M.A. and Bertaux, J.-L. and Bertini, I. and Besse, S. and Bodewits, D. and Cremonese,, G. and Da Deppo, V. and Davidsson, B. and De Cecco, M. and Debei, S. and Güttler, C. and Fornasier, S. and Fulle, M. and Groussin, O. and Gutierrez, P.J. and Hviid, S.F. and Ip, W.-H. and Jorda, L. and Knollenberg, J. and Kovacs, G. and Kramm, J.-R. and Kührt, E. and Küppers, M. and La Forgia, F. and Lara, L.M. and Lazzarin, M. and Lopez Moreno, J. J. and Marchi, S. and Marzari, F. and Michalik, H. and Naletto, G. and Oklay, N. and Pommerol, A. and Preusker, F. and Scholten, F. and Tubiana, C. and Vincent, J.-B. (2015) Regional surface morphology of comet 67P/Churyumov-Gerasimenko from Rosetta/OSIRIS images. Astronomy & Astrophysics 583 , A26. ISSN 0004-6361.
Abstract
Aims. The OSIRIS camera onboard the Rosetta spacecraft has been acquiring images of the comet 67P/Churyumov-Gerasimenko (67P)’s nucleus at spatial resolutions down to ~0.17 m/px ever since Aug. 2014. These images have yielded unprecedented insight into the morphological diversity of the comet’s surface. This paper presents an overview of the regional morphology of comet 67P. Methods. We used the images that were acquired at orbits ~20–30 km from the center of the comet to distinguish different regions on the surface and introduce the basic regional nomenclature adopted by all papers in this Rosetta special feature that address the comet’s morphology and surface processes. We used anaglyphs to detect subtle regional and topographical boundaries and images from close orbit (~10 km from the comet’s center) to investigate the fine texture of the surface. Results. Nineteen regions have currently been defined on the nucleus based on morphological and/or structural boundaries, and they can be grouped into distinctive region types. Consolidated, fractured regions are the most common region type. Some of these regions enclose smooth units that appear to settle in gravitational sinks or topographically low areas. Both comet lobes have a significant portion of their surface covered by a dusty coating that appears to be recently placed and shows signs of mobilization by aeolian-like processes. The dusty coatings cover most of the regions on the surface but are notably absent from a couple of irregular large depressions that show sharp contacts with their surroundings and talus-like deposits in their interiors, which suggests that short-term explosive activity may play a significant role in shaping the comet’s surface in addition to long-term sublimation loss. Finally, the presence of layered brittle units showing signs of mechanical failure predominantly in one of the comet’s lobes can indicate a compositional heterogeneity between the two lobes.
Metadata
Item Type: | Article |
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Keyword(s) / Subject(s): | comets, general / comets, individual, 67P/Churyumov-Gerasimenko / methods, observational |
School: | Birkbeck Faculties and Schools > Faculty of Science > School of Natural Sciences |
Depositing User: | Administrator |
Date Deposited: | 17 Oct 2018 11:24 |
Last Modified: | 02 Aug 2023 17:45 |
URI: | https://eprints.bbk.ac.uk/id/eprint/24699 |
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