Large heterogeneities in comet 67P as revealed by active pits from sinkhole collapse

Please use this identifier to cite or link to this item: https://ir.lib.ncu.edu.tw/handle/987654321/101521

Title:	Large heterogeneities in comet 67P as revealed by active pits from sinkhole collapse
Authors:	林忠義;Vincent, Jean-Baptiste;Bodewits, Dennis;Besse, Sébastien;Sierks, Holger;Barbieri, Cesare;Lamy, Philippe;Rodrigo, Rafael;Koschny, Detlef;Rickman, Hans;Keller, Horst Uwe;Agarwal, Jessica;A'Hearn, Michael F.;Auger, Anne-Thérèse;Barucci, M. Antonella;Bertaux, Jean-Loup;Bertini, Ivano;Capanna, Claire;Cremonese, Gabriele;Da Deppo, Vania;Davidsson, Björn;Debei, Stefano;De Cecco, Mariolino;El-Maarry, Mohamed Ramy;Ferri, Francesca;Fornasier, Sonia;Fulle, Marco;Gaskell, Robert;Giacomini, Lorenza;Groussin, Olivier;Guilbert-Lepoutre, Aurélie;Gutierrez-Marques, P.;Gutiérrez, Pedro J.;Güttler, Carsten;Hoekzema, Nick;Höfner, Sebastian;Hviid, Stubbe F.;Ip, Wing-Huen;Jorda, Laurent;Knollenberg, Jörg;Kovacs, Gabor;Kramm, Rainer;Kührt, Ekkehard;Küppers, Michael;La Forgia, Fiorangela;Lara, Luisa M.;Lazzarin, Monica;Lee, Vicky;Leyrat, Cédric;Lin, Zhong-Yi;Lopez Moreno, Josè J.;Lowry, Stephen;Magrin, Sara;Maquet, Lucie;Marchi, Simone;Marzari, Francesco;Massironi, Matteo;Michalik, Harald;Moissl, Richard;Mottola, Stefano;Naletto, Giampiero;Oklay, Nilda;Pajola, Maurizio;Preusker, Frank;Scholten, Frank;Thomas, Nicolas;Toth, Imre;Tubiana, Cecilia
Contributors:	理學院天文研究所
Keywords:	639/33/445/848;Astrophysics;Comets;Earth and Planetary Astrophysics;Holes;Humanities and Social Sciences;letter;Morphology;multidisciplinary;Natural history;Observations;Science;Sciences of the Universe;Sinkholes;Space exploration;Spacecraft;Spatial distribution;Sublimation
Date:	2015-07-01
Issue Date:	2026-04-21 14:36:58 (UTC+8)
Publisher:	Nature Publishing Group;London: Nature Publishing Group UK
Abstract:	摘要： The size and spatial distribution of pits on comet 67P/Churyumov–Gerasimenko, which are active and probably created by a sinkhole process, imply that large heterogeneities exist in the physical, structural or compositional properties of the first few hundred metres below the current cometary surface. A pit stop for Rosetta Using data from the OSIRIS camera onboard ESA's Rosetta probe, Jean-Baptiste Vincent et al . have been able to examine cometary pits — a surface feature detected on many cometary nuclei — with unprecedented spatial resolution and with varying viewing geometries. The pits on comet 67P/Churyumov–Gerasimenko are shown to be active and probably created by a sinkhole process. The authors propose that after formation, the pits expand slowly in diameter with sublimation-driven retreat of the walls. The size and spatial distribution of pits implies large heterogeneities in physical, structural or compositional properties of the first few hundred metres below the current surface. Pits have been observed on many cometary nuclei mapped by spacecraft 1 , 2 , 3 , 4 . It has been argued that cometary pits are a signature of endogenic activity, rather than impact craters such as those on planetary and asteroid surfaces. Impact experiments 5 , 6 and models 7 , 8 cannot reproduce the shapes of most of the observed cometary pits, and the predicted collision rates imply that few of the pits are related to impacts 8 , 9 . Alternative mechanisms like explosive activity 10 have been suggested, but the driving process remains unknown. Here we report that pits on comet 67P/Churyumov–Gerasimenko are active, and probably created by a sinkhole process, possibly accompanied by outbursts. We argue that after formation, pits expand slowly in diameter, owing to sublimation-driven retreat of the walls. Therefore, pits characterize how eroded the surface is: a fresh cometary surface will have a ragged structure with many pits, while an evolved surface will look smoother. The size and spatial distribution of pits imply that large heterogeneities exist in the physical, structural or compositional properties of the first few hundred metres below the current nucleus surface. 其他題名： Nature 出版者： London: Nature Publishing Group UK 出版日期： 2015-07-02 出處： Nature (London), 2015-07, Vol.523 (7558), p.63-66 資源來源： SpringerLink Journals 版權： Springer Nature Limited 2015 版權： COPYRIGHT 2015 Nature Publishing Group 版權： Copyright Nature Publishing Group Jul 2, 2015 版權： CC0 1.0 - Universal 識別號： ISSN: 0028-0836 識別號： ISSN: 1476-4687 識別號： EISSN: 1476-4687 識別號： DOI: 10.1038/nature14564 識別號： PMID: 26135448 識別號： CODEN: NATUAS
Appears in Collections:	[Graduate Institute of Astronomy] journal & Dissertation

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