Vincent, J.-B. and Bodewits, D. and Besse, S. and Sierks, H. and Barbieri, C. and Lamy, P. and Rodrigo, R. and Koschny, D. and Rickman, H. 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 Capanna, C. and Cremonese, G. and Da Deppo, V. and Davidsson, B. and Debei, S. and De Cecco, M. and El-Maarry, Mohamed Ramy and Ferri, F. and Fornasier, S. and Fulle, M. and Gaskell, R. and Giacomini, L. and Groussin, O. and Guilbert-Lepoutre, A. and Gutierrez-Marques, P. and Gutiérrez, P.J. and Güttler, C. and Hoekzema, N. and Höfner, S. and Hviid, S.F. and Ip, W.-H. and Jorda, L. and Knollenberg, J. and Kovacs, G. and Kramm, R. and Kührt, E. and Küppers, M. and La Forgia, F. and Lara, L.M. and Lazzarin, M. and Lee, V. and Leyrat, C. and Lin, Z.-Y. and Lopez Moreno, J.J. and Lowry, S. and Magrin, S. and Maquet, L. and Marchi, S. and Marzari, F. and Massironi, M. and Michalik, H. and Moissl, R. and Mottola, S. and Naletto, G. and Oklay, N. and Pajola, M. and Preusker, F. and Scholten, F. and Thomas, N. and Toth, I. and Tubiana, C. (2015) Large heterogeneities in comet 67P as revealed by active pits from sinkhole collapse. Nature 523 (7558), pp. 63-66. ISSN 0028-0836.
Abstract
Pits have been observed on many cometary nuclei mapped by spacecraft1,2,3,4. 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 experiments5,6 and models7,8 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 impacts8,9. Alternative mechanisms like explosive activity10 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.
Metadata
Item Type: | Article |
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School: | Birkbeck Faculties and Schools > Faculty of Science > School of Natural Sciences |
Depositing User: | Administrator |
Date Deposited: | 20 Nov 2018 14:30 |
Last Modified: | 02 Aug 2023 17:46 |
URI: | https://eprints.bbk.ac.uk/id/eprint/25204 |
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