Thermal fracturing on comets
International audience We simulate the stresses induced by temperature changes in a putative hard layer near the surface of comet 67P/Churyumov-Gerasimenko with a thermo-viscoelastic model. Such a layer could be formed by the recondensation or sintering of water ice (and dust grains), as suggested b...
Published in: | Astronomy & Astrophysics |
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Online Access: | https://hal.science/hal-02108715 https://hal.science/hal-02108715/document https://hal.science/hal-02108715/file/Attree_etal_2018b.pdf https://doi.org/10.1051/0004-6361/201731937 |
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ftunivaixmarseil:oai:HAL:hal-02108715v1 2024-05-12T08:05:05+00:00 Thermal fracturing on comets Thermal fracturing on comets: Applications to 67P/Churyumov-Gerasimenko Attree, N. Groussin, O. Jorda, L. Rodionov, S. Auger, A.-T. Thomas, N. Brouet, Y. Poch, O. Kührt, Ekkehard Knapmeyer, M. Preusker, F. Scholten, F. Knollenberg, J. Hviid, S. Hartogh, P. 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) Universität Bern / University of Bern (UNIBE) Physikalisches Institut Bern DLR Institute of Planetary Research German Aerospace Center (DLR) Deutsches Zentrum für Luft- und Raumfahrt (DLR) Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS) Max-Planck-Gesellschaft 2018 https://hal.science/hal-02108715 https://hal.science/hal-02108715/document https://hal.science/hal-02108715/file/Attree_etal_2018b.pdf https://doi.org/10.1051/0004-6361/201731937 en eng HAL CCSD EDP Sciences info:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361/201731937 hal-02108715 https://hal.science/hal-02108715 https://hal.science/hal-02108715/document https://hal.science/hal-02108715/file/Attree_etal_2018b.pdf doi:10.1051/0004-6361/201731937 info:eu-repo/semantics/OpenAccess ISSN: 0004-6361 EISSN: 1432-0756 Astronomy and Astrophysics - A&A https://hal.science/hal-02108715 Astronomy and Astrophysics - A&A, 2018, 610, pp.A76. ⟨10.1051/0004-6361/201731937⟩ comets: general comets: individual: 67P/Churyumov-Gerasimenko planets and satellites: physical evolution [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] info:eu-repo/semantics/article Journal articles 2018 ftunivaixmarseil https://doi.org/10.1051/0004-6361/201731937 2024-04-18T00:34:39Z International audience We simulate the stresses induced by temperature changes in a putative hard layer near the surface of comet 67P/Churyumov-Gerasimenko with a thermo-viscoelastic model. Such a layer could be formed by the recondensation or sintering of water ice (and dust grains), as suggested by laboratory experiments and computer simulations, and would explain the high compressive strength encountered by experiments on board the Philae lander. Changes in temperature from seasonal insolation variation penetrate into the comet's surface to depths controlled by the thermal inertia, causing the material to expand and contract. Modelling this with a Maxwellian viscoelastic response on a spherical nucleus, we show that a hard, icy layer with similar properties to Martian permafrost will experience high stresses: up to tens of MPa, which exceed its material strength (a few MPa), down to depths of centimetres to a metre. The stress distribution with latitude is confirmed qualitatively when taking into account the comet's complex shape but neglecting thermal inertia. Stress is found to be comparable to the material strength everywhere for sufficient thermal inertia (50 J m −2 K −1 s −1/2) and ice content (45% at the equator). In this case, stresses penetrate to a typical depth of ∼0.25 m, consistent with the detection of metre-scale thermal contraction crack polygons all over the comet. Thermal fracturing may be an important erosion process on cometary surfaces which breaks down material and weakens cliffs. Article in Journal/Newspaper Ice permafrost Aix-Marseille Université: HAL Astronomy & Astrophysics 610 A76 |
institution |
Open Polar |
collection |
Aix-Marseille Université: HAL |
op_collection_id |
ftunivaixmarseil |
language |
English |
topic |
comets: general comets: individual: 67P/Churyumov-Gerasimenko planets and satellites: physical evolution [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] |
spellingShingle |
comets: general comets: individual: 67P/Churyumov-Gerasimenko planets and satellites: physical evolution [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] Attree, N. Groussin, O. Jorda, L. Rodionov, S. Auger, A.-T. Thomas, N. Brouet, Y. Poch, O. Kührt, Ekkehard Knapmeyer, M. Preusker, F. Scholten, F. Knollenberg, J. Hviid, S. Hartogh, P. Thermal fracturing on comets |
topic_facet |
comets: general comets: individual: 67P/Churyumov-Gerasimenko planets and satellites: physical evolution [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph] |
description |
International audience We simulate the stresses induced by temperature changes in a putative hard layer near the surface of comet 67P/Churyumov-Gerasimenko with a thermo-viscoelastic model. Such a layer could be formed by the recondensation or sintering of water ice (and dust grains), as suggested by laboratory experiments and computer simulations, and would explain the high compressive strength encountered by experiments on board the Philae lander. Changes in temperature from seasonal insolation variation penetrate into the comet's surface to depths controlled by the thermal inertia, causing the material to expand and contract. Modelling this with a Maxwellian viscoelastic response on a spherical nucleus, we show that a hard, icy layer with similar properties to Martian permafrost will experience high stresses: up to tens of MPa, which exceed its material strength (a few MPa), down to depths of centimetres to a metre. The stress distribution with latitude is confirmed qualitatively when taking into account the comet's complex shape but neglecting thermal inertia. Stress is found to be comparable to the material strength everywhere for sufficient thermal inertia (50 J m −2 K −1 s −1/2) and ice content (45% at the equator). In this case, stresses penetrate to a typical depth of ∼0.25 m, consistent with the detection of metre-scale thermal contraction crack polygons all over the comet. Thermal fracturing may be an important erosion process on cometary surfaces which breaks down material and weakens cliffs. |
author2 |
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) Universität Bern / University of Bern (UNIBE) Physikalisches Institut Bern DLR Institute of Planetary Research German Aerospace Center (DLR) Deutsches Zentrum für Luft- und Raumfahrt (DLR) Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS) Max-Planck-Gesellschaft |
format |
Article in Journal/Newspaper |
author |
Attree, N. Groussin, O. Jorda, L. Rodionov, S. Auger, A.-T. Thomas, N. Brouet, Y. Poch, O. Kührt, Ekkehard Knapmeyer, M. Preusker, F. Scholten, F. Knollenberg, J. Hviid, S. Hartogh, P. |
author_facet |
Attree, N. Groussin, O. Jorda, L. Rodionov, S. Auger, A.-T. Thomas, N. Brouet, Y. Poch, O. Kührt, Ekkehard Knapmeyer, M. Preusker, F. Scholten, F. Knollenberg, J. Hviid, S. Hartogh, P. |
author_sort |
Attree, N. |
title |
Thermal fracturing on comets |
title_short |
Thermal fracturing on comets |
title_full |
Thermal fracturing on comets |
title_fullStr |
Thermal fracturing on comets |
title_full_unstemmed |
Thermal fracturing on comets |
title_sort |
thermal fracturing on comets |
publisher |
HAL CCSD |
publishDate |
2018 |
url |
https://hal.science/hal-02108715 https://hal.science/hal-02108715/document https://hal.science/hal-02108715/file/Attree_etal_2018b.pdf https://doi.org/10.1051/0004-6361/201731937 |
genre |
Ice permafrost |
genre_facet |
Ice permafrost |
op_source |
ISSN: 0004-6361 EISSN: 1432-0756 Astronomy and Astrophysics - A&A https://hal.science/hal-02108715 Astronomy and Astrophysics - A&A, 2018, 610, pp.A76. ⟨10.1051/0004-6361/201731937⟩ |
op_relation |
info:eu-repo/semantics/altIdentifier/doi/10.1051/0004-6361/201731937 hal-02108715 https://hal.science/hal-02108715 https://hal.science/hal-02108715/document https://hal.science/hal-02108715/file/Attree_etal_2018b.pdf doi:10.1051/0004-6361/201731937 |
op_rights |
info:eu-repo/semantics/OpenAccess |
op_doi |
https://doi.org/10.1051/0004-6361/201731937 |
container_title |
Astronomy & Astrophysics |
container_volume |
610 |
container_start_page |
A76 |
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1798847346721685504 |