Ancient and present surface evolution processes in the Ash region of comet 67P/Churyumov-Gerasimenko
| Autor: | Laurent Jorda, François Costard, A. Bouquety, Sylvain Bouley, A. Séjourné, Olivier Groussin |
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| Přispěvatelé: | Géosciences Paris Saclay (GEOPS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS) |
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
010504 meteorology & atmospheric sciences
Comet FOS: Physical sciences Detailed data surfaces 01 natural sciences Physics - Geophysics 0103 physical sciences Cliff comets individual Digital elevation model 010303 astronomy & astrophysics Geomorphology ComputingMilieux_MISCELLANEOUS 0105 earth and related environmental sciences Earth and Planetary Astrophysics (astro-ph.EP) geography geography.geographical_feature_category 67P/Churyumov-Gerasimenko -methods Astronomy and Astrophysics Landslide data analysis -planets and satellites Geophysics (physics.geo-ph) Morphometric analysis 13. Climate action Space and Planetary Science [SDU]Sciences of the Universe [physics] Physics - Data Analysis Statistics and Probability Geology Data Analysis Statistics and Probability (physics.data-an) Astrophysics - Earth and Planetary Astrophysics |
| Zdroj: | Astronomy and Astrophysics-A&A Astronomy and Astrophysics-A&A, EDP Sciences, In press, ⟨10.1051/0004-6361/202140516⟩ Astronomy and Astrophysics-A&A, 2021, 649, ⟨10.1051/0004-6361/202140516⟩ Astronomy and Astrophysics-A&A, EDP Sciences, 2021, 649, ⟨10.1051/0004-6361/202140516⟩ |
| ISSN: | 0004-6361 |
| DOI: | 10.1051/0004-6361/202140516⟩ |
| Popis: | Aims. The Rosetta mission provided us with detailed data of the surface of the nucleus of comet 67P/Churyumov-Gerasimenko. In order to better understand the physical processes associated with the comet activity and the surface evolution of its nucleus, we performed a detailed comparative morphometrical analysis of two depressions located in the Ash region. Methods. To detect morphological temporal changes, we compared pre- and post-perihelion high-resolution (pixel scale of 0.07–1.75 m) OSIRIS images of the two depressions. We quantified the changes using the dynamic heights and the gravitational slopes calculated from the digital terrain model of the studied area. In particular, we measured seven geometric parameters associated with the two depressions (length, three width values, height, area, and volume) using the ArcGIS software before and after perihelion. Results. Our comparative morphometrical analysis allowed us to detect and quantify the temporal changes that occurred in two depressions of the Ash region during the last perihelion passage. We find that the two depressions grew by several meters. The area of the smallest depression (structure I) increased by 90 ± 20%, with two preferential growths: one close to the cliff associated with the apparition of new boulders at its foot, and a second one on the opposite side of the cliff. The largest depression (structure II) grew in all directions, increasing in area by 20 ± 5%, and no new deposits have been detected. We interpreted these two depression changes as being driven by the sublimation of ices, which explains their global growth and which can also trigger landslides. The deposits associated with depression II reveal a stair-like topography, indicating that they have accumulated during several successive landslides from different perihelion passages. Overall, these observations bring additional evidence of complex active processes and reshaping events occurring on short timescales (months to years), such as depression growth and landslides, and on longer timescales (decades to millenniums), such as cliff retreat. |
| Databáze: | OpenAIRE |
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