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62 results on '"Benoit Langlais"'

1. Megashears and hydrothermalism at the Martian crustal dichotomy in Valles Marineris

Author: Joanna Gurgurewicz, Daniel Mège, Frédéric Schmidt, Sylvain Douté, and Benoit Langlais
Subjects: Geology, QE1-996.5, Environmental sciences, GE1-350
Abstract: Brittle-ductile deformation of hydrothermally altered mafic basement rocks on Mars may pin-point the location of base and rare metals and constrain Mars’ earliest crustal evolution, according to structural, spectral and geomagnetic mapping
Published: 2022
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2. Martian Bow Shock Oscillations Driven by Solar Wind Variations: Simultaneous Observations From Tianwen‐1 and MAVEN

Author: Long Cheng, Robert Lillis, Yuming Wang, Anna Mittelholz, Shaosui Xu, David L. Mitchell, Catherine Johnson, Zhenpeng Su, Jasper S. Halekas, Benoit Langlais, Tielong Zhang, Guoqiang Wang, Sudong Xiao, Zhuxuan Zou, Zhiyong Wu, Yutian Chi, Zonghao Pan, Kai Liu, Xinjun Hao, Yiren Li, Manming Chen, Jared Espley, Frank Eparvier, and Shannon Curry
Subjects: Geophysics. Cosmic physics, QC801-809
Abstract: Abstract The Martian bow shock stands as the first defense against the solar wind and shapes the Martian magnetosphere. Previous studies showed the correlation between the Martian bow shock location and solar wind parameters. Here we present direct evidence of solar wind effects on the Martian bow shock by analyzing Tianwen‐1 and MAVEN data. We examined three cases where Tianwen‐1 data show rapid oscillations of the bow shock, while MAVEN data record changes in solar wind plasma and magnetic field. The results indicate that the bow shock is rapidly compressed and then expanded during the dynamic pressure pulse in the solar wind, and is also oscillated during the IMF rotation. The superposition of variations in multiple solar wind parameters leads to more intensive bow shock oscillation. This study emphasizes the importance of joint observations by Tianwen‐1 and MAVEN for studying the real‐time response of the Martian magnetosphere to the solar wind.
Published: 2023
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3. Open Magnetic Fields in the Martian Magnetosphere Revealing Dipole-like Intrinsic Magnetic Fields at Mars

Author: Shaosui Xu, Janet G. Luhmann, David L. Mitchell, Tristan Weber, David A. Brain, Yingjuan Ma, Shannon M. Curry, Gina A. DiBraccio, Jasper Halekas, Suranga Ruhunusiri, Christian Mazelle, Robert J. Lillis, and Benoit Langlais
Subjects: Mars, Solar-planetary interactions, Magnetic fields, Interplanetary magnetic fields, Magnetic anomalies, Astrophysics, QB460-466
Abstract: Mars’s magnetosphere is hybrid, having contributions from both an induced magnetosphere like Venus and the localized crustal magnetic fields. However, the planetary fields also include large-scale, more global components. In this study, we investigate their role in Mars’s magnetospheric topological responses to the interplanetary magnetic field (IMF) clock angle using observations from the Mars Atmospheric Volatile and EvolutioN mission. We show that the large-scale planetary field has a “dipole-like” influence on the Mars global magnetosphere by examining the open field topology. We find that the “dipole-like” planetary field, as at Earth, results in a more open magnetosphere during southward IMF. The clock angle effects on the twisted magnetotail current sheet are similarly consistent with this analogy. It reinforces the idea that Mars’s magnetosphere and solar wind interaction are more Earth-like than previously thought.
Published: 2023
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4. Exploring Martian Magnetic Fields with a Helicopter

Author: Anna Mittelholz, Lindsey Heagy, Catherine L. Johnson, Jonathan Bapst, Jared Espley, Abigail A. Fraeman, Benoit Langlais, Robert Lillis, and William Rapin
Subjects: Mars, Solar system terrestrial planets, Planetary magnetospheres, Planetary science, Planetary interior, Planetary structure, Astronomy, QB1-991
Abstract: The era of helicopter-based surveys on Mars has already begun, creating opportunities for future aerial science investigations with a range of instruments. We argue that magnetometer-based studies can make use of aerial technology to answer some of the key questions regarding early Mars evolution. As such, we discuss mission concepts for a helicopter equipped with a magnetometer on Mars, measurements it would provide, and survey designs that could be implemented. For a range of scenarios, we build magnetization models and test how well structures can be resolved using a range of different inversion approaches. With this work, we provide modeling ground work and recommendations to plan the future of aerial Mars exploration.
Published: 2023
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5. Crustal and time-varying magnetic fields at the InSight landing site on Mars

Author: Christopher T. Russell, Matthew Fillingim, Sabine Stanley, Lu Pan, Benoit Langlais, William B. Banerdt, Peter Chi, Catherine L. Johnson, Chloé Michaut, Aymeric Spiga, Philippe Lognonné, Don Banfield, François Forget, Veronique Ansan, Steve Joy, Yanan Yu, Mark A. Wieczorek, Anna Mittelholz, Suzanne E. Smrekar, Shea N. Thorne, C. Quantin-Nataf, Matthew P. Golombek, H. Haviland, Xinping Liu, Department of Earth, Ocean and Atmospheric Sciences [Vancouver] (UBC EOAS), University of British Columbia (UBC), Planetary Science Institute [Tucson] (PSI), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Department of Earth, Planetary and Space Sciences [Los Angeles] (EPSS), University of California [Los Angeles] (UCLA), University of California-University of California, Cornell University [New York], Earth, Planetary and Space Sciences, University of California, Los Angeles, CA, USA., Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Marshall Space Flight Center, Huntsville, AL, USA, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Earth, Planetary and Space Sciences, University of California, Los Angeles, CA, USA, Institut de Physique du Globe de Paris (IPGP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement [Lyon] (LGL-TPE), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-École normale supérieure - Lyon (ENS Lyon), Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA, Morton K. Blaustein Department of Earth and Planetary Sciences [Baltimore], Johns Hopkins University (JHU), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Joseph Louis LAGRANGE (LAGRANGE), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), InSight Project at the Jet Propulsion Laboratory, California Institute of Technology National Aeronautics & Space Administration (NASA) InSight Participating Scientist Program Canadian Space Agency Centre National D'etudes Spatiales Green Foundation for Earth Sciences during leave at the Institute of Geophysics and Planetary Physics, Scripps Institution of Oceanography (2019-2020), University of California (UC)-University of California (UC), University of California [Berkeley] (UC Berkeley), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Université Nice Sophia Antipolis (1965 - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de la Côte d'Azur, and COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Martian, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 010504 meteorology & atmospheric sciences, Field (physics), MANTLE, Mars Exploration Program, Geophysics, 010502 geochemistry & geophysics, 01 natural sciences, Physics::Geophysics, Magnetic field, Atmosphere, Magnetization, Solar wind, ELECTRICAL-CONDUCTIVITY, [SDU]Sciences of the Universe [physics], 13. Climate action, Physics::Space Physics, General Earth and Planetary Sciences, Astrophysics::Earth and Planetary Astrophysics, MOON, Geology, 0105 earth and related environmental sciences, Dynamo
Abstract: Magnetic fields provide a window into a planet’s interior structure and evolution, including its atmospheric and space environments. Satellites at Mars have measured crustal magnetic fields indicating an ancient dynamo. These crustal fields interact with the solar wind to generate transient fields and electric currents in Mars’s upper atmosphere. Surface magnetic field data play a key role in understanding these effects and the dynamo. Here we report measurements of magnetic field strength and direction at the InSight (Interior Exploration using Seismic Investigations, Geodesy and Heat Transport) landing site on Mars. We find that the field is ten times stronger than predicted by satellite-based models. We infer magnetized rocks beneath the surface, within ~150 km of the landing site, consistent with a past dynamo with Earth-like strength. Geological mapping and InSight seismic data suggest that much or all of the magnetization sources are carried in basement rocks, which are at least 3.9 billion years old and are overlain by between 200 m and ~10 km of lava flows and modified ancient terrain. Daily variations in the magnetic field indicate contributions from ionospheric currents at 120 km to 180 km altitude. Higher-frequency variations are also observed; their origin is unknown, but they probably propagate from even higher altitudes to the surface. We propose that the time-varying fields can be used to investigate the electrical conductivity structure of the martian interior. The magnetic field measured by the InSight lander on Mars varies daily and is ten times stronger than expected. The field is inferred to originate from components of basement rocks magnetized by an ancient dynamo of Earth-like strength.
Published: 2020

6. Investigating Mercury's Environment with the Two-Spacecraft BepiColombo Mission

Author: Oleg Korablev, M. Fujimoto, Léa Griton, Cesare Grava, Masafumi Hirahara, Hirotsugu Kojima, S. Barabash, Wolfgang Baumjohann, A. Martindale, Chuanfei Dong, François Leblanc, Chris Carr, S. T. Lindsay, Yasumasa Kasaba, M. Kobayashi, Herbert Lichtenegger, Philippe-A. Bourdin, Karri Muinonen, J. S. Oliveira, Jan-Erik Wahlund, Ferdinand Plaschke, Christina Plainaki, S. M. P. McKenna-Lawlor, Dominique Delcourt, Eric Quémerais, Xianzhe Jia, Dusan Odstrcil, James A. Slavin, V. Mangano, M. G. Pelizzo, Benoit Langlais, Joe Zender, Emma J. Bunce, Ichiro Yoshikawa, Peter Wurz, Stavro Ivanovski, Stefano Massetti, George C. Ho, Y. Saito, Juhani Huovelin, Suzanne M. Imber, Sae Aizawa, Alessandro Mura, Jim M. Raines, Ayako Matsuoka, F. Sahraoui, Karl-Heinz Glassmeier, Pierre Henri, Rami Vainio, Matthew K. James, Rosemary M. Killen, Stefano Orsini, Shahab Fatemi, Tomas Karlsson, Monica Laurenza, Esa Kallio, Christoph Lhotka, Michiko Morooka, Johannes Benkhoff, David A. Rothery, Yasuhito Narita, Michel Moncuquet, Anna Milillo, Alexey A. Berezhnoy, Satoshi Yagitani, Adam Masters, F. Califano, Manuel Grande, Stefano Livi, Daniel Heyner, Emilia Kilpua, G. Murakami, Jan Deca, S. de la Fuente, R. Moissl, Bernard V. Jackson, Kanako Seki, N. André, M. Dósa, Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), Istituto Nazionale di Astrofisica (INAF), Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency [Sagamihara] (JAXA), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Wigner Research Centre for Physics [Budapest], Hungarian Academy of Sciences (MTA), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Space Research Centre [Leicester], University of Leicester, Department of Space and Plasma Physics [Stockholm], KTH School of Electrical Engineering, Royal Institute of Technology [Stockholm] (KTH )-Royal Institute of Technology [Stockholm] (KTH ), NASA Goddard Space Flight Center (GSFC), Space Technology Ireland Limited, Department of Climate and Space Sciences and Engineering (CLaSP), School of Physical Sciences [Milton Keynes], Faculty of Science, Technology, Engineering and Mathematics [Milton Keynes], The Open University [Milton Keynes] (OU)-The Open University [Milton Keynes] (OU), Space Research Institute of Austrian Academy of Sciences (IWF), Austrian Academy of Sciences (OeAW), Sternberg Astronomical Institute [Moscow], Lomonosov Moscow State University (MSU), University of Pisa - Università di Pisa, University of Colorado [Boulder], European Space Astronomy Centre (ESAC), Princeton Plasma Physics Laboratory (PPPL), Princeton University, Department of Astrophysical Sciences [Princeton], Southwest Research Institute [San Antonio] (SwRI), Swedish Institute of Space Physics [Kiruna] (IRF), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), INAF - Osservatorio Astronomico di Trieste (OAT), University of California [San Diego] (UC San Diego), University of California (UC), Department of Electronics and Nanoengineering [Espoo], School of Electrical Engineering [Aalto Univ], Aalto University-Aalto University, Planetary Plasma and Atmospheric Research Center [Sendai] (PPARC), Tohoku University [Sendai], Department of Physics [Helsinki], Falculty of Science [Helsinki], Helsingin yliopisto = Helsingfors universitet = University of Helsinki-Helsingin yliopisto = Helsingfors universitet = University of Helsinki, Planetary Exploration Research Center [Chiba] (PERC), Chiba Institute of Technology (CIT), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), HELIOS - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Blackett Laboratory, Imperial College London, Swedish Institute of Space Physics [Uppsala] (IRF), Institute of Physics [Graz], Karl-Franzens-Universität Graz, Centro de Investigação da Terra e do Espaço da UC (CITEUC), Universidade de Coimbra [Coimbra], CNR Institute for Photonics and Nanotechnologies (IFN), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Italian Space Agency, Laboratoire de Physique des Plasmas (LPP), Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École polytechnique (X)-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Department of Earth and Planetary Science [Tokyo], Graduate School of Science [Tokyo], The University of Tokyo (UTokyo)-The University of Tokyo (UTokyo), Space Research Laboratory [Turku] (SRL), Department of Physics and Astronomy [Turku], University of Turku-University of Turku, Physics Institute [Bern], University of Bern, Department of Physics [Imperial College London], Institute of Mathematical and Physical Sciences [Aberystwyth], University of Wales, Institute for Space-Earth Environmental Research [Nagoya] (ISEE), Nagoya University, Space Research Institute of the Russian Academy of Sciences (IKI), Russian Academy of Sciences [Moscow] (RAS), Research Institute for Sustainable Humanosphere (RISH), Kyoto University, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Graduate School of the Natural Science and Technology [Kanazawa], Kanazawa University (KU), Department of Complexity Science and Engineering [Tokyo], The University of Tokyo (UTokyo), European Space Agency (ESA), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES), University of California, University of Helsinki-University of Helsinki, Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), Karl-Franzens-Universität [Graz, Autriche], Consiglio Nazionale delle Ricerche [Roma] (CNR), Kyoto University [Kyoto], Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), The Royal Society, Science and Technology Facilities Council, INAF National Institute for Astrophysics, JAXA Institute of Space and Astronautical Science, European Space Research and Technology Centre, IRAP, Hungarian Academy of Sciences, Technical University of Braunschweig, Johns Hopkins Applied Physics Laboratory, University of Michigan, Ann Arbor, KTH Royal Institute of Technology, NASA Goddard Space Flight Center, Space Technology Ireland, Open University Milton Keynes, Austrian Academy of Sciences, Lomonosov Moscow State University, University of Pisa, University of Colorado Boulder, European Space Astronomy Centre, Princeton Plasma Physics Laboratory, Southwest Research Institute, Uppsala University, Université d'Orléans, Osservatorio Astronomico di Trieste, University of California San Diego, Department of Electronics and Nanoengineering, Tohoku University, University of Helsinki, Chiba Institute of Technology, Université de Nantes, Sorbonne Université, University of Graz, National Research Council of Italy, Agenzia Spaziale Italiana, The University of Tokyo, University of Turku, Aberystwyth University, Space Research Institute of the Russian Academy of Sciences, Université de Versailles Saint-Quentin-en-Yvelines, Kanazawa University, Aalto-yliopisto, and Aalto University
Subjects: 010504 meteorology & atmospheric sciences, Computer science, BepiColombo, chemistry.chemical_element, FOS: Physical sciences, Astronomy & Astrophysics, 01 natural sciences, Mercury’s environment, Fusion, plasma och rymdfysik, Interplanetary dust cloud, Astronomi, astrofysik och kosmologi, 0201 Astronomical and Space Sciences, 0103 physical sciences, Astronomy, Astrophysics and Cosmology, Exosphere, Magnetosphere, Aerospace engineering, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), 0105 earth and related environmental sciences, Scientific instrument, Earth and Planetary Astrophysics (astro-ph.EP), Spacecraft, business.industry, 520 Astronomy, Astronomy and Astrophysics, 620 Engineering, Fusion, Plasma and Space Physics, Mercury (element), Solar wind, Planetary science, chemistry, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Mercury's environment, Mercury’s environment · Magnetosphere · Exosphere · BepiColombo, Astrophysics - Instrumentation and Methods for Astrophysics, business, Astrophysics - Earth and Planetary Astrophysics
Abstract: The ESA-JAXA BepiColombo mission will provide simultaneous measurements from two spacecraft, offering an unprecedented opportunity to investigate magnetospheric and exospheric dynamics at Mercury as well as their interactions with the solar wind, radiation, and interplanetary dust. Many scientific instruments onboard the two spacecraft will be completely, or partially devoted to study the near-space environment of Mercury as well as the complex processes that govern it. Many issues remain unsolved even after the MESSENGER mission that ended in 2015. The specific orbits of the two spacecraft, MPO and Mio, and the comprehensive scientific payload allow a wider range of scientific questions to be addressed than those that could be achieved by the individual instruments acting alone, or by previous missions. These joint observations are of key importance because many phenomena in Mercury's environment are highly temporally and spatially variable. Examples of possible coordinated observations are described in this article, analysing the required geometrical conditions, pointing, resolutions and operation timing of different BepiColombo instruments sensors., Comment: 78 pages, 14 figures, published
Published: 2022
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7. A Spherical Harmonic Model of Earth's Lithospheric Magnetic Field up to Degree 1050

Author: Erwan Thébault, Gauthier Hulot, Pierre Vigneron, Benoit Langlais, Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement et la société-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de Physique du Globe de Paris (IPGP), and Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)
Subjects: 010504 meteorology & atmospheric sciences, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Swarm behaviour, Spherical harmonics, Geophysics, 010502 geochemistry & geophysics, 01 natural sciences, Magnetic field, Degree (temperature), Lithosphere, General Earth and Planetary Sciences, Geology, Earth (classical element), ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: International audience
Published: 2021

8. Compositional Enhancement of Crustal Magnetization on Mars

Author: Christopher S. Edwards, Benoit Langlais, J. Buz, A. Alhantoobi, Joseph O'Rourke, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), and Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010504 meteorology & atmospheric sciences, Magnetism, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Mars Exploration Program, Geophysics, 01 natural sciences, Magnetic field, Magnetization, 0103 physical sciences, General Earth and Planetary Sciences, Spectroscopy, 010303 astronomy & astrophysics, Geology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Dynamo
Abstract: International audience
Published: 2021

9. Mars’ Ancient Dynamo and Crustal Remanent Magnetism

Author: Foteini Vervelidou, John E. P. Connerney, Achim Morschhauser, Benoit Langlais, Dhananjay Ravat, Cari L. Johnson, Anna Mittelholz, Benjamin P. Weiss, Roger R. Fu, Jared Espley, Robert Lillis, and Michael W. R. Volk
Subjects: Magnetism, Mars Exploration Program, Geology, Dynamo, Astrobiology
Published: 2021

10. Critical knowledge gaps in the Martian geological record: A rationale for regional-scale in situ exploration by rotorcraft mid-air deployment

Author: Valerie Payre, Bethany L. Ehlmann, N. Mangold, Robert Lillis, J. Bapst, Sylvestre Maurice, Violaine Sautter, A. A. Fraeman, William Rapin, Benoit Langlais, Jessica Flahaut, Anna Mittelholz, Arya Udry, David Baratoux, James Tuttle Keane, Gilles Dromart, C. Quantin-Nataf, and Briony Horgan
Subjects: Martian, Scale (ratio), Software deployment, Earth science, Geologic record, Geology
Published: 2021

11. Geodesy, Geophysics and Fundamental Physics Investigations of the BepiColombo Mission

Author: Nicola Tosi, Paolo Cappuccio, Francesco Santoli, Tim Van Hoolst, J. S. Oliveira, Daniel Heyner, Nicolas Thomas, Alexander Stark, Johannes Wicht, Luciano Iess, H. Hussmann, Ivan di Stefano, Antonio Genova, Johannes Benkhoff, Patrick Kolhey, Johannes Z. D. Mieth, Gregor Steinbrügge, Benoit Langlais, Genova, A. [0000-0001-5584-492X], Hussmann, H. [0000-0002-3816-0232], Van Hoolst, T. [0000-0002-9820-8584], Heyner, D. [0000-0001-7894-8246], Iess, L. [0000-0002-6230-5825], Santoli, F. [0000-0003-2493-0109], Thomas, N. [0000-0002-0146-0071], Cappuccio, P. [0000-0002-8758-6627], Di Stefano, I. [0000-0003-1491-6848], Langlais, B. [0000-0001-5207-304X], Oliveira, J. S. [0000-0002-4587-2895], Stark, A. [0000-0001-9110-1138], Steinbrügge, G. [0000-0002-1050-7759], Tosi, N. [0000-0002-4912-2848], Wicht, J. [0000-0002-2440-5091], Benkhoff, J. [0000-0002-4307-9703], Agenzia Spaziale Italiana (ASI), Bundesministerium für Wirtschaft und Energie (BMWi), Deutsches Zentrum für Luft- und Raumfahrt (DLR), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), and Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Solar System, Engineering, Topography, 010504 meteorology & atmospheric sciences, BepiColombo, Gravity, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], chemistry.chemical_element, Astronomy & Astrophysics, 01 natural sciences, law.invention, Orbiter, Theories of gravitation, Planetenphysik, Planet, law, 0103 physical sciences, Altimeter, Internal structure, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Radio Science, Science & Technology, Spacecraft, business.industry, 520 Astronomy, Planetengeodäsie, Astronomy and Astrophysics, Geophysics, Mercury, Geodesy, 620 Engineering, Mercury (element), Planetary science, Magnetic field, chemistry, 13. Climate action, Space and Planetary Science, gravity, internal structure, magnetic field, theories of gravitation, thermal evolution, topography, Physical Sciences, business, Thermal evolution
Abstract: Open access funding provided by Università degli Studi di Roma La Sapienza within the CRUI-CARE Agreement. In preparation for the ESA/JAXA BepiColombo mission to Mercury, thematic working groups had been established for coordinating the activities within the BepiColombo Science Working Team in specific fields. Here we describe the scientific goals of the Geodesy and Geophysics Working Group (GGWG) that aims at addressing fundamental questions regarding Mercury’s internal structure and evolution. This multidisciplinary investigation will also test the gravity laws by using the planet Mercury as a proof mass. The instruments on the Mercury Planetary Orbiter (MPO), which are devoted to accomplishing the GGWG science objectives, include the BepiColombo Laser Altimeter (BELA), the Mercury orbiter radio science experiment (MORE), and the MPO magnetometer (MPO-MAG). The onboard Italian spring accelerometer (ISA) will greatly aid the orbit reconstruction needed by the gravity investigation and laser altimetry. We report the current knowledge on the geophysics, geodesy, and evolution of Mercury after the successful NASA mission MESSENGER and set the prospects for the BepiColombo science investigations based on the latest findings on Mercury’s interior. The MPO spacecraft of the BepiColombo mission will provide extremely accurate measurements of Mercury’s topography, gravity, and magnetic field, extending and improving MESSENGER data coverage, in particular in the southern hemisphere. Furthermore, the dual-spacecraft configuration of the BepiColombo mission with the Mio spacecraft at higher altitudes than the MPO spacecraft will be fundamental for decoupling the internal and external contributions of Mercury’s magnetic field. Thanks to the synergy between the geophysical instrument suite and to the complementary instruments dedicated to the investigations on Mercury’s surface, composition, and environment, the BepiColombo mission is poised to advance our understanding of the interior and evolution of the innermost planet of the solar system. We are grateful to the ESA spacecraft operations team for supporting and planning the scientific observations during BepiColombo cruise and orbital mission. A.G. and L.I. thank A. Di Ruscio (Sapienza University of Rome) for his support in the numerical simulations of the MORE investigation. A.G. and L.I. acknowledge funding from the Italian Space Agency (ASI) grant N. 2017-40-H.0. T.V.H. was financially supported by the Belgian Research Action through Interdisciplinary Networks (BRAIN.be 2.0 project STEM) and by the Belgian PRODEX program managed by the European Space Agency in collaboration with the Belgian Federal Science Policy Office. D.H. was financially supported by the German Ministerium für Wirtschaft und Energie and the German Zentrum für Luft- und Raumfahrt under contract 50 QW 1501. F.S. was financially supported by ASI through the cooperation agreement N. 2017-47-H.0. We acknowledge Gregory A. Neumann and an anonymous referee for their helpful comments to improve the quality of this paper. The data used in this study for the numerical simulations of the BepiColombo mission are available at https://www.cosmos.esa.int/web/spice/spice-for-bepicolombo. Peerreview
Published: 2021

12. International Geomagnetic Reference Field: the thirteenth generation

Author: Ciaran Beggan, Santiago Marsal, Martin Rother, Johannes Wicht, Valeriy G. Petrov, Fco. Javier Pavón-Carrasco, Shin'ya Nakano, Nils Olsen, William R. Brown, Vincent Lesur, M. C. Nair, Xuhui Shen, Alexandre Fournier, N. R. Schnepf, Monika Korte, Terence J. Sabaka, Benoit Langlais, T. Bondar, Lars Tøffner-Clausen, Werner Magnes, Takuto Minami, Thomas Jager, Andrew Tangborn, Alexander Grayver, Gauthier Hulot, Guillaume Ropp, J. Matzka, Christopher C. Finlay, J. E. Mound, Joan Miquel Torta, Sabrina Sanchez, Grace Cox, Diana Saturnino, Foteini Vervelidou, Alexey Kuvshinov, A. Woods, Pierre Vigneron, M. C. Metman, Hagay Amit, Hiroaki Toh, Loïc Huder, Jean-Michel Leger, Matthias Holschneider, Nicolas Gillet, Erwan Thébault, Ingo Wardinski, Susan Macmillan, Weijia Kuang, Clemens Kloss, Achim Morschhauser, Yanyan Yang, Z. Zeren, Claudia Stolle, Julien Aubert, Philip W. Livermore, Patrick Alken, Aude Chambodut, S. Califf, Magnus Danel Hammer, Mioara Mandea, Bin Zhou, J. Varner, Julien Baerenzung, F. J. Lowes, Arnaud Chulliat, Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado [Boulder]-National Oceanic and Atmospheric Administration (NOAA), NOAA National Centers for Environmental Information (NCEI), National Oceanic and Atmospheric Administration (NOAA), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), British Geological Survey [Edinburgh], British Geological Survey (BGS), Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), University of Applied Sciences Potsdam (FHP), Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation (IZMIRAN), Russian Academy of Sciences [Moscow] (RAS), Institut de physique du globe de Strasbourg (IPGS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Louis Pasteur - Strasbourg I-Centre National de la Recherche Scientifique (CNRS), Division of Geomagnetism, DTU Space, Technical, Technical University of Denmark [Lyngby] (DTU), Université Grenoble Alpes (UGA), Institute of Geophysics [ETH Zürich], Department of Earth Sciences [Swiss Federal Institute of Technology - ETH Zürich] (D-ERDW), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Département Systèmes (DSYS), Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), German Research Centre for Geosciences - Helmholtz-Centre Potsdam (GFZ), NASA Goddard Space Flight Center (GSFC), School of Earth and Environment [Leeds] (SEE), University of Leeds, University of Northumbria at Newcastle [United Kingdom], Austrian Academy of Sciences, Centre National d’Études Spatiales [Paris] (CNES), Observatori de l'Ebre (OE), Universitat Ramon Llull [Barcelona] (URL)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Graduate School of Environmental Studies [Nagoya], Nagoya University, The Institute of Statistical Mathematics (Tokyo ), Universidad Complutense de Madrid = Complutense University of Madrid [Madrid] (UCM), Instituto de Geociencias [Madrid] (IGEO), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Universidad Complutense de Madrid = Complutense University of Madrid [Madrid] (UCM), Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Institute of Crustal Dynamics [Beijing], China Earthquake Administration (CEA), Division of Earth and Planetary Sciences [Kyoto], Kyoto University [Kyoto], State Key Laboratory of Space Weather, National Space Science Center, Institut de Physique du Globe de Paris (IPGP (UMR_7154)), Institut national des sciences de l'Univers (INSU - CNRS)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Danmarks Tekniske Universitet = Technical University of Denmark (DTU), Universidad Complutense de Madrid = Complutense University of Madrid [Madrid] (UCM)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Kyoto University, and Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Universitat Ramon Llull [Barcelona] (URL)
Subjects: Magnetic declination, IGRF, Magnetic feld modeling, Geomagnetism, 010504 meteorology & atmospheric sciences, Field (physics), [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], lcsh:Geodesy, 010502 geochemistry & geophysics, 01 natural sciences, Physics::Geophysics, 0105 earth and related environmental sciences, lcsh:QB275-343, Previous generation, Epoch (reference date), Aeronomy, lcsh:QE1-996.5, lcsh:Geography. Anthropology. Recreation, Física atmosférica, Spherical harmonics, Geology, Geodesy, Secular variation, lcsh:Geology, lcsh:G, Space and Planetary Science, Physics::Space Physics, International Geomagnetic Reference Field, Astrophysics::Earth and Planetary Astrophysics, Magnetic field modeling
Abstract: Earth, Planets and Space, 73 (1), ISSN:1343-8832, ISSN:1880-5981
Published: 2021

13. Electrical conductivity and temperature of the Earth's mantle inferred from Bayesian inversion of Swarm vector magnetic data

Author: Erwan Thébault, Benoit Langlais, Aymeric Houliez, O. Verhoeven, Diana Saturnino, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Institut de Recherche pour le Développement et la société-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne (UCA), and Royal Observatory of Belgium [Brussels] (ROB)
Subjects: Physics, 010504 meteorology & atmospheric sciences, Physics and Astronomy (miscellaneous), Field (physics), [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Gauss, Mantle temperature, Astronomy and Astrophysics, Probability density function, Geophysics, Conductivity, 010502 geochemistry & geophysics, 01 natural sciences, Mantle (geology), Magnetic field, 13. Climate action, Space and Planetary Science, Lithosphere, Electrical resistivity and conductivity, Electrical conductivity, Swarm, 0105 earth and related environmental sciences
Abstract: International audience; Study of induced magnetic field is a powerful way to sound Earth internal structure. This work presents a full analysis and interpretation in terms of electrical conductivity and temperature of vector magnetic field measurements from Swarm Level1b data product from 26/11/2013 to 31/12/2019. Time series of the Gauss coefficients associated with the induced and inducing magnetic field are obtained from the data after removal of the core and lithospheric fields models and data selection. A Bayesian inversion of the induced field Gauss coefficients is then performed to obtain a new estimate of Earth's 1D mantle electrical conductivity down to 2000 km depth. This profile is fully compatible with the profiles derived from satellite and ground magnetic observatories data but does not present in the lower mantle the increase predicted by laboratory-based conductivity profile associated to classical mantle composition and temperature profile. Using the most recent database to model the electrical conductivity of all mineral mantle phases, two different methods are used to interpret Swarm data in terms of temperature for a given composition and water content. The first one is based on an interpretation of the conductivity estimates in terms of temperature by classical numerical root search. The second one consists in inferring a temperature probability density function from a Bayesian inversion of the Gauss coefficients associated to the induced magnetic field. Our results show that the later provide more reliable estimates of mantle temperatures, in relation to more physically grounded prior values. This second method provides also tighter constraints on the electrical conductivity estimates of the lower mantle.
Published: 2021

14. The Origin of Observed Magnetic Variability for a Sol on Mars From InSight

Author: Catherine L. Johnson, E. Barrett, Christopher T. Russell, François Forget, Aymeric Spiga, Steven P. Joy, S. N. Thorne, William B. Banerdt, Sue Smrekar, Benoit Langlais, Anna Mittelholz, Matthew Fillingim, Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), and Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010504 meteorology & atmospheric sciences, Mars Exploration Program, 01 natural sciences, Astrobiology, Geophysics, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, Space and Planetary Science, Geochemistry and Petrology, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), Ionosphere, 010303 astronomy & astrophysics, Geology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: International audience
Published: 2020

15. Geomagnetic core field models and secular variation forecasts for the 13th International Geomagnetic Reference Field (IGRF-13)

Author: Mioara Mandea, Erwan Thébault, Hagay Amit, Aude Chambodut, Diana Saturnino, Ingo Wardinski, Benoit Langlais, Institut de physique du globe de Strasbourg (IPGS), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre National d’Études Spatiales [Paris] (CNES), Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), and Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Institut national des sciences de l'Univers (INSU - CNRS)
Subjects: Geomagnetic field models, 010504 meteorology & atmospheric sciences, Field (physics), lcsh:Geodesy, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, 010502 geochemistry & geophysics, 01 natural sciences, Physics::Geophysics, Satellite altitude, The geomagnetic field, Singular spectrum analysis, 0105 earth and related environmental sciences, Forecasts of the geomagnetic field, lcsh:QB275-343, Geomagnetic secular variation, lcsh:QE1-996.5, lcsh:Geography. Anthropology. Recreation, Geology, Geophysics, Secular variation, lcsh:Geology, Earth's magnetic field, lcsh:G, Space and Planetary Science, Physics::Space Physics, International Geomagnetic Reference Field, Astrophysics::Earth and Planetary Astrophysics
Abstract: Observations of the geomagnetic field taken at Earth's surface and at satellite altitude were combined to construct continuous models of the geomagnetic field and its secular variation from 1957 to 2020. From these parent models, we derive candidate main field models for the epochs 2015 and 2020 to the 13th generation of the International Geomagnetic Reference Field (IGRF). The secular variation candidate model for the period 2020 - 2025 is derived from a forecast of the secular variation in 2022.5, which results from a multi-variate singular spectrum analysis of the secular variation from 1957 to 2020.
Published: 2020

16. A first comparison between ionospheric and surface level magnetic fields at Mars

Author: Matthew O Fillingim, Catherine L. Johnson, Anna Magdalena Mittelholz, Benoit Langlais, Christopher T. Russell, Steven P. Peter Joy, Peter J Chi, Robert James Lillis, Jared Randolph Espley, Suzanne E. Smrekar, William Bruce Banerdt, and Bruce M. Jakosky
Published: 2020

17. A thick crustal block revealed by reconstructions of early Mars highlands

Author: Brigitte Zanda, François Costard, James Tuttle Keane, V. Sautter, Sylvain Bouley, Antoine Séjourné, Olivier Vanderhaeghe, Benoit Langlais, Isamu Matsuyama, R. H. Hewins, David Baratoux, Valerie Payre, Géosciences Paris Saclay (GEOPS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Institut de Mécanique Céleste et de Calcul des Ephémérides (IMCCE), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Lille-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), California Institute of Technology (CALTECH), Géosciences Environnement Toulouse (GET), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Lunar and Planetary Laboratory [Tucson] (LPL), University of Arizona, Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Rice University [Houston], Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), and Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS)
Subjects: [PHYS]Physics [physics], geography, geography.geographical_feature_category, 010504 meteorology & atmospheric sciences, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Crust, Volcanism, Mars Exploration Program, 010502 geochemistry & geophysics, 01 natural sciences, Mantle (geology), Elysium, Paleontology, Volcano, [SDU]Sciences of the Universe [physics], General Earth and Planetary Sciences, Upwelling, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Geology, 0105 earth and related environmental sciences, Tharsis
Abstract: International audience; The global-scale crustal structure of Mars is shaped by impact basins, volcanic provinces, and a hemispheric dichotomy with a thin crust beneath the northern lowlands and a thick crust beneath the southern highlands. The southern highlands are commonly treated as a coherent terrain of ancient crust with a common origin and shared geologic history, plausibly originating from a giant impact(s) or a hemispheric-scale mantle upwelling. Previous studies have quantified the contribution of volcanism to this crustal structure; however, the influence of large impacts remains unclear. Here we present reconstructions of the past crustal thickness of Mars (about 4.2 Gyr ago) where the four largest impact basins (Hellas, Argyre, Isidis and Utopia) are removed, assuming mass conservation, as well as the main volcanic provinces of Tharsis and Elysium. Our reconstruction shows more subdued crustal thickness variations than at present, although the crustal dichotomy persists. However, our reconstruction reveals a region of discontinuous patches of thick crust in the southern highlands associated with magnetic and geochemical anomalies. This region, corresponding to Terra Cimmeria–Sirenum, is interpreted as a discrete crustal block. Our findings suggest that the southern highlands are composed of several crustal blocks with different geological histories. Such a complex architecture of the southern highlands is not explained by existing scenarios for crustal formation and evolution. A discrete block of thick ancient crust revealed by a crustal reconstruction suggests a complex geologic history for the southern highlands of Mars.
Published: 2020

18. In situ and remote characterization of the external field temporal variations at Mars

Author: Erwan Thébault, Benoit Langlais, and François Civet
Subjects: In situ, 010504 meteorology & atmospheric sciences, Mars Exploration Program, 01 natural sciences, Characterization (materials science), Magnetic field, Geophysics, Space and Planetary Science, Geochemistry and Petrology, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), External field, 010303 astronomy & astrophysics, Geology, 0105 earth and related environmental sciences, Remote sensing
Published: 2017

19. Timing of the martian dynamo: New constraints for a core field 4.5 and 3.7 Ga ago

Author: Joshua M. Feinberg, Catherine L. Johnson, Benoit Langlais, Roger J. Phillips, Anna Mittelholz, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), and Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Martian, Multidisciplinary, 010504 meteorology & atmospheric sciences, Field (physics), Physics, SciAdv r-articles, Crust, Geophysics, Structural basin, 010502 geochemistry & geophysics, 01 natural sciences, Billion years, Magnetic field, Magnetization, 13. Climate action, [SDU]Sciences of the Universe [physics], Geology, Research Articles, 0105 earth and related environmental sciences, Dynamo, Research Article
Abstract: MAVEN magnetic field data indicate that a martian dynamo field was active 4.5 and 3.7 Ga ago., The absence of crustal magnetic fields above the martian basins Hellas, Argyre, and Isidis is often interpreted as proof of an early, before 4.1 billion years (Ga) ago, or late, after 3.9 Ga ago, dynamo. We revisit these interpretations using new MAVEN magnetic field data. Weak fields are present over the 4.5-Ga old Borealis basin, with the transition to strong fields correlated with the basin edge. Magnetic fields, confined to a near-surface layer, are also detected above the 3.7-Ga old Lucus Planum. We conclude that a dynamo was present both before and after the formation of the basins Hellas, Utopia, Argyre, and Isidis. A long-lived, Earth-like dynamo is consistent with the absence of magnetization within large basins if the impacts excavated large portions of strongly magnetic crust and exposed deeper material with lower concentrations of magnetic minerals.
Published: 2019

20. Constraining the Early History of Mercury and Its Core Dynamo by Studying the Crustal Magnetic Field

Author: Lon L. Hood, J. S. Oliveira, Benoit Langlais, Agence Spatiale Européenne (ESA), European Space Agency (ESA), University of Arizona, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), and Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010504 meteorology & atmospheric sciences, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], chemistry.chemical_element, Geophysics, 01 natural sciences, Magnetic field, Mercury (element), chemistry, 13. Climate action, Space and Planetary Science, Geochemistry and Petrology, Earth and Planetary Sciences (miscellaneous), Space Science, Magnetic anomaly, Geology, 0105 earth and related environmental sciences, Dynamo
Abstract: International audience; Key Points: 9 • We analyze crustal magnetic anomalies that are likely thermoremanent and ob-10 tain the corresponding paleopole positions. 11 • All best fitting paleopoles are found in the Southern Hemisphere. 12 • Our study strongly suggests that Mercury has evolved with time. Abstract 14 Low altitude magnetic field data acquired by MESSENGER over a small portion of Mer-15 cury's surface revealed weak crustal magnetic field signatures. Here we study the crustal 16 magnetic anomalies associated with impact craters on Mercury. We assume that the sources 17 of these anomalies consist of impact melt, enriched in impactor iron. We assume that 18 the subsurfaces of Mercury's impact craters have cooled in the presence of a constant 19 global magnetic field, thus becoming thermoremanently magnetized. We invert for the 20 crustal magnetization direction within five craters using a unidirectional magnetization 21 model which assumes that the melt impact rocks recorded the constant core magnetic 22 field present when the crater was formed, and that the crater's magnetization has not 23 been altered since its formation. From the best fitting magnetization direction we then 24 obtain the corresponding north magnetic paleopole position assuming a centered core 25 dipolar field. Results show that all five magnetic paleopoles lie in the Southern Hemi-26 sphere but are not required to be located near the present-day magnetic pole, which lies 27 near the south geographic pole. Accounting for the uncertainties, we show that our re-28 sults all agree in a common small region that excludes the current magnetic pole. This 29 strongly suggests that the dynamo has evolved with time. Our results represent valu-30 able information for understanding the evolution of Mercury, and emphasize the impor-31 tance of including more anomaly analyses to complete and refine our conclusions. 32
Published: 2019

21. The evolution of Martian Crustal Magnetic Field from MGS to MAVEN and Insight missions

Author: Benoit Langlais
Abstract: The evolution of Martian Crustal Magnetic Field from MGS to MAVEN and Insight missionseng
Published: 2019
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22. A New Model of the Crustal Magnetic Field of Mars Using MGS and MAVEN

Author: Michael E. Purucker, Erwan Thébault, Robert Lillis, Aymeric Houliez, Benoit Langlais, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), and Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Martian, 010504 meteorology & atmospheric sciences, Field (physics), Magnetometer, Geophysics, Mars Exploration Program, Atmosphere of Mars, 01 natural sciences, Article, law.invention, Magnetic field, Magnetization, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, 13. Climate action, Space and Planetary Science, Geochemistry and Petrology, law, 0103 physical sciences, Dynamo theory, Earth and Planetary Sciences (miscellaneous), 010303 astronomy & astrophysics, Geology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: While devoid of an active magnetic dynamo field today, Mars possesses a remanent magnetic field that may reach several thousand nanoteslas locally. The exact origin and the events that have shaped the crustal magnetization remain largely enigmatic. Three magnetic field data sets from two spacecraft collected over 13 cumulative years have sampled the Martian magnetic field over a range of altitudes from 90 up to 6,000 km: (a) Mars Global Surveyor (MGS) magnetometer (1997–2006), (b) MGS Electron Reflectometer (1999–2006), and (c) Mars Atmosphere and Volatile EvolutioN (MAVEN) magnetometer (2014 to today). In this paper we combine these complementary data sets for the first time to build a new model of the Martian internal magnetic field. This new model improves upon previous ones in several aspects: comprehensive data coverage, refined data selection scheme, modified modeling scheme, discrete-to-continuous transformation of the model, and increased model resolution. The new model has a spatial resolution of ∼160 km at the surface, corresponding to spherical harmonic degree 134. It shows small scales and well-defined features, which can now be associated with geological signatures.
Published: 2019

23. Correlated Time‐Varying Magnetic Fields and the Core Size of Mercury

Author: Erwan Thébault, Ingo Wardinski, Benoit Langlais, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), and Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, 010504 meteorology & atmospheric sciences, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], chemistry.chemical_element, 01 natural sciences, Molecular physics, Magnetic field, Mercury (element), Geophysics, chemistry, 13. Climate action, Space and Planetary Science, Geochemistry and Petrology, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: International audience; Mercury is characterized by a very peculiar magnetic field, as it was revealed by the MESSENGER mission. Its internal component is highly axisymmetric, dominated by the dipole, and very weak. This in turns leads to a very dynamic magnetosphere. It is known that there exist relationships between the internally generated field and the external field, although their dynamics are complex. In this study we derive steady and time‐varying spherical harmonic models of Mercury's magnetic field using MESSENGER measurements and interpret these models both in terms of correlated features and of the internal structure of Mercury. The influence of the hemispheric data distribution of MESSENGER is evaluated to grant the robustness of our models. We find a quadrupole‐to‐dipole ratio of 0.27 for the steady magnetic field. The time‐varying models reveal periodic and highly correlated temporal variations of internal and external origins. This argues for externally inducing and internally induced sources. The main period is 88 days, the orbital period of Mercury around the Sun. There is no measurable time lag between variations of external and internal magnetic fields, which place an upper limit of 1 S/m for the mantle conductivity. Finally, the compared amplitudes of external and internal time‐varying field lead to an independent (from gravity studies) estimate of the conductive core radius, at 2,060 ± 22 km. These analyses will be further completed with the upcoming BepiColombo mission and its magnetic field experiment, but the presented results already lift the veil on some of the magnetic oddities at Mercury.
Published: 2019

24. Pre-mission InSights on the Interior of Mars

Author: Mélanie Drilleau, O. Verhoeven, Matthew P. Golombek, Philippe Lognonné, Anna Mittelholz, Ana-Catalina Plesa, Antoine Mocquet, Benoit Langlais, Robert Myhill, Tamara Gudkova, T. Pike, Catherine L. Johnson, Henri Samuel, Suzanne E. Smrekar, Renee Weber, W. Bruce Banerdt, Martin van Driel, Domenico Giardini, Amir Khan, Tim Van Hoolst, William M. Folkner, Doris Breuer, Mark P. Panning, Véronique Dehant, Clément Perrin, Raphaël F. Garcia, Matthias Grott, Nobuaki Fuji, Ulrich R. Christensen, Mark A. Wieczorek, Simon Stähler, Tilman Spohn, Attilio Rivoldini, Institut de Physique du Globe de Paris (IPGP), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Université Paris Diderot - Paris 7 (UPD7)-IPG PARIS-Institut national des sciences de l'Univers (INSU - CNRS), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Laboratoire de Planétologie et Géodynamique UMR6112 (LPG), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-Université d'Angers (UA), Joseph Louis LAGRANGE (LAGRANGE), Université Nice Sophia Antipolis (... - 2019) (UNS), Université Côte d'Azur (UCA)-Université Côte d'Azur (UCA)-Observatoire de la Côte d'Azur, Université Côte d'Azur (UCA)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Côte d'Azur (UCA)-Université Nice Sophia Antipolis (... - 2019) (UNS), COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Observatoire de la Côte d'Azur, COMUE Université Côte d'Azur (2015-2019) (COMUE UCA)-Université Côte d'Azur (UCA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut Supérieur de l'Aéronautique et de l'Espace - ISAE-SUPAERO (FRANCE), and UCL - SST/ELI/ELIC - Earth & Climate
Subjects: Convection, Solar System, 010504 meteorology & atmospheric sciences, Mars, crust, Volcanism, 01 natural sciences, Mantle (geology), Physics::Geophysics, Planetary internal structure, 0103 physical sciences, Thermal, Traitement du signal et de l'image, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, core, Crust, Astronomy and Astrophysics, Mars Exploration Program, Geophysics, interior structure, Planetary science, 13. Climate action, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, InSight, Interior, Seismology, Heat flow, Geodesy, Mantle, Core, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing, Geology, mantle
Abstract: International audience; Abstract The Interior exploration using Seismic Investigations, Geodesy, and Heat Trans-port (InSight) Mission will focus on Mars’ interior structure and evolution. The basic structure of crust, mantle, and core form soon after accretion. Understanding the early differentiation process on Mars and how it relates to bulk composition is key to improving our understanding of this process on rocky bodies in our solar system, as well as in other solar systems. Current knowledge of differentiation derives largely from the layers observed via seismology on the Moon. However, the Moon’s much smaller diameter make it a poor analog with respect to interior pressure and phase changes. In this paper we review the current knowledge of the thickness of the crust, the diameter and state of the core, seismic attenuation, heat flow, and interior composition. InSight will conduct the first seismic and heat flow measurements of Mars, as well as more precise geodesy. These data reduce uncertainty in crustal thickness, core size and state, heat flow, seismic activity and meteorite impact rates by a factor of 3–10× relative to previous estimates. Based on modeling of seismic wave propagation, we can further constrain interior temperature, composition, and the location of phase changes. By combining heat flow and a well constrained value of crustal thickness, we can estimate the distribution of heat producing elements between the crust and mantle. All of these quantities are key inputs to models of interior convection and thermal evolution that predict the processes that control subsurface temperature, rates of volcanism, plume distribution and stability, and convective state. Collectively these factors offer strong controls on the overall evolution of the geology and habitability of Mars.
Published: 2019

25. A comparative analysis of the magnetic field signals over impact structures on the Earth, Mars and the Moon

Author: Benoit Langlais, Mioara Mandea, Michael E. Purucker, and Anca Isac
Subjects: Atmospheric Science, 010504 meteorology & atmospheric sciences, Demagnetizing field, Aerospace Engineering, Astronomy and Astrophysics, Geophysics, Mars Exploration Program, 01 natural sciences, Magnetic flux, Physics::Geophysics, Astrobiology, Magnetic field, Dipole, Magnetic field of the Moon, Impact crater, Space and Planetary Science, Physics::Space Physics, 0103 physical sciences, Hypervelocity, General Earth and Planetary Sciences, Astrophysics::Earth and Planetary Astrophysics, 010303 astronomy & astrophysics, Geology, 0105 earth and related environmental sciences
Abstract: An improved description of magnetic fields of terrestrial bodies has been obtained from recent space missions, leading to a better characterization of the internal fields including those of crustal origin. One of the striking differences in their crustal magnetic field is the signature of large impact craters. A comparative analysis of the magnetic characteristics of these structures can shed light on the history of their respective planetary-scale magnetic dynamos. This has motivated us to identify impact craters and basins, first by their quasi-circular features from the most recent and detailed topographic maps and then from available global magnetic field maps. We have examined the magnetic field observed above 27 complex craters on the Earth, 34 impact basins on Mars and 37 impact basins on the Moon. For the first time, systematic trends in the amplitude and frequency of the magnetic patterns, inside and outside of these structures are observed for all three bodies. The demagnetization effects due to the impact shock wave and excavation processes have been evaluated applying the Equivalent Source Dipole forward modeling approach. The main characteristics of the selected impact craters are shown. The trends in their magnetic signatures are indicated, which are related to the presence or absence of a planetary-scale dynamo at the time of their formation and to impact processes. The low magnetic field intensity at center can be accepted as the prime characteristic of a hypervelocity impact and strongly associated with the mechanics of impact crater formation. In the presence of an active internal field, the process of demagnetization due to the shock impact is associated with post-impact remagnetization processes, generating a more complex magnetic signature.
Published: 2016

26. The New Magnetic Figures Of Mars

Author: Benoit Langlais, Erwan Thébault, Aymeric Houliez, Michales E. Purucker, and Rober J. Lillis
Abstract: New magnetic figures of Mars
Published: 2018
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27. The Mars 2020 Candidate Landing Sites: A Magnetic Field Perspective

Author: Catherine L. Johnson, Benoit Langlais, Anna Mittelholz, Foteini Vervelidou, Achim Morschhauser, Benjamin P. Weiss, Robert Lillis, Department of Earth, Ocean and Atmospheric Sciences [Vancouver] (UBC EOAS), University of British Columbia (UBC), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Space Sciences Laboratory [Berkeley] (SSL), University of California [Berkeley], University of California-University of California, Massachusetts Institute of Technology (MIT), Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, and Weiss, Benjamin P
Subjects: Paleomagnetism, 010504 meteorology & atmospheric sciences, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Perspective (graphical), Mars Exploration Program, Environmental Science (miscellaneous), 010502 geochemistry & geophysics, 01 natural sciences, Astrobiology, Magnetic field, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, 13. Climate action, General Earth and Planetary Sciences, ComputingMilieux_MISCELLANEOUS, Geology, 0105 earth and related environmental sciences
Abstract: We present an analysis of the remaining three candidate landing sites for Mars 2020, Columbia Hills (CH), Northeast Syrtis (NES) and Jezero (JE) from the perspective of understanding Mars' crustal magnetic field. We identify how the different sites can address each of six community-defined paleomagnetic science objectives for Mars return samples. These objectives include understanding the early dynamo field and its variability, identification of magnetic minerals that carry magnetization in the samples, and characterization of any thermal and chemical alteration of samples. Satellite data have provided global and regional constraints on crustal magnetization, indicating strong magnetizations at CH and weak to no magnetization at JE and NES. However, the primary paleomagnetic interest—understanding the early dynamo—requires ground truth from a landing site at which pre-Noachian and Early Noachian deposits are accessible. This requirement is most likely met by the site NES, which contains meggabreccia deposits, and it is therefore the highest priority landing site for magnetic field investigations. Importantly, a sample return mission has never been done, and so any of the three landing sites will provide critical, new data that will contribute to understanding the history of Mars' magnetic field and crustal mineralogy and, in turn, yield constraints on the planet's evolution. Keywords: Mars 2020; paleomagnetism; Mars; magnetic field
Published: 2018
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28. A modified Equivalent Source Dipole method to model partially distributed magnetic field measurements, with application to Mercury

Author: Maria Alexandra Pais, Benoit Langlais, J. S. Oliveira, and Hagay Amit
Subjects: Physics, 010504 meteorology & atmospheric sciences, Field (physics), Geophysics, Dipole model of the Earth's magnetic field, 01 natural sciences, L-shell, Magnetic field, Secular variation, Dipole, 13. Climate action, Space and Planetary Science, Geochemistry and Petrology, Sidereal time, Physics::Space Physics, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), Astrophysics::Earth and Planetary Astrophysics, Mercury's magnetic field, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: Hermean magnetic field measurements acquired over the northern hemisphere by the MErcury Surface Space ENvironment GEochemistry, and Ranging (MESSENGER) spacecraft provide crucial information on the magnetic field of the planet. We develop a new method, the Time Dependent Equivalent Source Dipole, to model a planetary magnetic field and its secular variation over a limited spatial region. Tests with synthetic data distributed on regular grids as well as at spacecraft positions show that our modeled magnetic field can be upward or downward continued in an altitude range of −300 to 1460 km for regular grids and in a narrower range of 10 to 970 km for spacecraft positions. They also show that the method is not sensitive to a very weak secular variation along MESSENGER orbits. We then model the magnetic field of Mercury during the first four individual sidereal days as measured by MESSENGER using the modified Equivalent Source Dipoles scheme and excluding the secular variation terms. We find a dominantly zonal field with small-scale nonaxisymmetric features corotating with the Sun in the Mercury Body Fixed system and repeating under similar local time, suggestive of external origin. When modeling the field during one complete solar day, these small-scale features decrease and the field becomes more axisymmetric. The lack of any coherent nonaxisymmetric feature recovered by our method, which was designed to allow for such small-scale structures, provides strong evidence for the large-scale and close-to-axisymmetry structure of the internal magnetic field of Mercury.
Published: 2015

29. The fate of early Mars' lost water: The role of serpentinization

Author: Eric Chassefière, François Leblanc, Benoit Langlais, and Yoann Quesnel
Subjects: 010504 meteorology & atmospheric sciences, Water on Mars, Accretion (meteorology), Atmospheric escape, Noachian, Mars Exploration Program, 01 natural sciences, Astrobiology, Atmosphere, Geophysics, 13. Climate action, Space and Planetary Science, Geochemistry and Petrology, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), Cryosphere, 010303 astronomy & astrophysics, Groundwater, Geology, 0105 earth and related environmental sciences
Abstract: The fate of water which was present on early Mars remains enigmatic. We propose a simple model based on serpentinization, a hydrothermal alteration process which may produce magnetite and store water. Our model invokes serpentinization during about 500 to 800 Myr, while a dynamo is active, which may have continued after the formation of the crustal dichotomy. We show that the present magnetic field measured by MGS in the Southern hemisphere is consistent with a ~500 m thick Global Equivalent Layer of water trapped in serpentine. Serpentinization results in the release of H 2 . The released H atoms are lost to space through thermal escape, increasing the D/H ratio in water reservoirs exchanging with atmosphere. We show that the value of the D/H ratio in the present atmosphere (~5) is consistent with the serpentinization of a ~500 m thick water GEL. We reassess the role of non-thermal escape in removing water from the planet. By considering an updated solar wind-ionosphere interaction representation, we show that the contribution of oxygen escape to H isotopic fractionation is negligible. Our results suggest that significant amounts of water (up to a ~330-1030 m thick GEL) present at the surface during the Noachian, similar to the quantity inferred from the morphological analysis of valley networks, could be stored today in subsurface serpentine. 1. The study Like Earth, Mars has been endowed with large amounts of water during accretion, equivalent to the content of several terrestrial oceans, corresponding to a several 10 km thick Global Equivalent Layer. The present inventory of observable water on Mars, mainly within the polar caps, is quite smaller, in the range from ~20-30 m. The mega-regolith capacity is large, with up to ~500 GEL m potentially trapped in the cryosphere, and hypothetically several additional hundreds of meters (up to ~500 m) of ground water surviving at depth below the cryosphere [1]. A ~500 m thick GEL is generally assumed to be required to explain the formation of outflow channels [2], and most of this water could be trapped today as water ice, and possibly deep liquid water, in the subsurface, and also possibly under the form of hydrated minerals.
Published: 2013

30. Early Mars serpentinization-derived CH4 reservoirs, H-2-induced warming and paleopressure evolution

Author: Yoann Quesnel, Jérémie Lasue, Eric Chassefière, Benoit Langlais, Géosciences Paris Sud (GEOPS), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire de Planétologie et Géodynamique UMR6112 (LPG), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-Université d'Angers (UA), Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Institut National de la Recherche Agronomique (INRA), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Collège de France (CdF (institution))-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut National de la Recherche Agronomique (INRA), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Géosciences Paris Saclay (GEOPS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), and Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)
Subjects: Martian, 010504 meteorology & atmospheric sciences, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Clathrate hydrate, Noachian, Mars Exploration Program, 01 natural sciences, Astrobiology, Atmosphere, Geophysics, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], 0103 physical sciences, Cryosphere, Hesperian, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, Geology, 0105 earth and related environmental sciences, Tharsis
Abstract: International audience; CH4 has been observed on Mars both by remote sensing and in situ during the past 15 yr. It could have been produced by early Mars serpentinization processes that could also explain the observed Martian remanent magnetic field. Assuming a cold early Mars, a cryosphere could trap such CH4 as clathrates in stable form at depth. The maximum storage capacity of such a clathrate cryosphere has been recently estimated to be 2 x 10(19) to 2 x 10(20) moles of methane. We estimate how large amounts of serpentinization-derived CH4 stored in the cryosphere have been released into the atmosphere during the Noachian and the early Hesperian. Due to rapid clathrate dissociation and photochemical conversion of CH4 to H-2, these episodes of massive CH4 release may have resulted in transient H-2-rich atmospheres, at typical levels of 10-20% in a background 1-2 bar CO2 atmosphere. The collision-induced heating effect of H-2 present in such an atmosphere has been shown to raise the surface temperature above the water freezing point. We show how local and rapid destabilization of the cryosphere can be induced by large events (such as the Hellas Basin or Tharsis bulge formation) and lead to such releases. Our results show that the early Mars cryosphere had a sufficient CH4 storage capacity to have maintained H-2-rich transient atmospheres during a total time period up to several million years or tens of million years, having potentially contributed to the formation of valley networks during the Noachian/early Hesperian.
Published: 2016

31. IGRF candidate models at times of rapid changes in core field acceleration

Author: Stefan Maus, Benoit Langlais, Arnaud Chulliat, Gauthier Hulot, Erwan Thébault, Michel Menvielle, Aude Chambodut, Institut de Physique du Globe de Paris (IPGP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), NOAA National Geophysical Data Center (NGDC), National Oceanic and Atmospheric Administration (NOAA), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de physique du globe de Strasbourg (IPGS), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), HELIOS - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Temporal extrapolation, Core field acceleration, 010504 meteorology & atmospheric sciences, Modeling, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Spherical harmonics, Geology, 010502 geochemistry & geophysics, Geodesy, 01 natural sciences, Main field, IGRF, Secular variation, Geomagnetic jerk, Magnetic field, Root mean square, symbols.namesake, Quadratic equation, Space and Planetary Science, Taylor series, symbols, A priori and a posteriori, 0105 earth and related environmental sciences
Abstract: International audience; We submit three candidate models following the call for IGRF-11. We apply a simple modeling approach in spherical harmonics based on a quadratic Taylor expansion for the internal field time variations. We use the Dst magnetic index as a proxy for the external field variations. In order to compensate for the limitations incurred by such a conventional approach, we focus on the optimal selection of satellite data in space and time. We also show that some a priori knowledge about the core field state helps us to avoid the pitfall encountered in the case of rapid changes of core field accelerations. Indeed, various acceleration events of relevance for the IGRF 11th occurred between 2003 and 2010, one of them being a geomagnetic jerk. They could entail disagreements between IGRF candidate models for the secular variation (SV) if data prior to 2008 are used. Our SV and main field (MF) candidate models have a root mean square uncertainty less than 6 nT/yr and 8 nT, respectively, with respect to the modeled magnetic field contributions. These values correspond to the intrinsic error associated with truncating SV and MF models to spherical harmonic degree 8 and 13, respectively, as requested for IGRF models.
Published: 2010

32. Modelling and inversion of local magnetic anomalies

Author: Armand Galdeano, Yoann Quesnel, Christophe Sotin, Benoit Langlais, and 2.3 Earth's Magnetic Field, 2.0 Physics of the Earth, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum
Subjects: Inverse, 550 - Earth sciences, Geology, Inversion (meteorology), Management, Monitoring, Policy and Law, Geodesy, Industrial and Manufacturing Engineering, Synthetic data, Nonlinear system, Dipole, Magnetization, Geophysics, A priori and a posteriori, Magnetic anomaly
Abstract: We present a method—named as MILMA for modelling and inversion of local magnetic anomalies—that combines forward and inverse modelling of aeromagnetic data to characterize both magnetization properties and location of unconstrained local sources. Parameters of simple-shape magnetized bodies (cylinder, prism or sphere) are first adjusted by trial and error to predict the signal. Their parameters provide a priori information for inversion of the measurements. Here, a generalized nonlinear approach with a least-squares criterion is adopted to seek the best parameters of the sphere (dipole). This inversion step allows the model to be more objectively adjusted to fit the magnetic signal. The validity of the MILMA method is demonstrated through synthetic and real cases using aeromagnetic measurements. Tests with synthetic data reveal accurate results in terms of depth source, whatever be the number of sources. The MILMA method is then used with real measurements to constrain the properties of the magnetized units of the Champtoceaux complex (France). The resulting parameters correlate with the crustal structure and properties revealed by other geological and geophysical surveys in the same area. The MILMA method can therefore be used to investigate the properties of poorly constrained lithospheric magnetized sources.
Published: 2008

33. International Geomagnetic Reference Field: the 12th generation

Author: Weijia Kuang, Valeriy G. Petrov, Aimin Du, Reyko Schachtschneider, Tatiana I. Zvereva, Ciaran Beggan, Stefan Maus, Vincent Lesur, Isabelle Fratter, Laura Brocco, Martin Rother, Olivier Sirol, Mohamed Hamoudi, Gauthier Hulot, Susan Macmillan, Arnaud Chulliat, Aude Chambodut, Terence J. Sabaka, Pierre Vigneron, F. J. Lowes, Benoit Langlais, Alan Thomson, T. Bondar, Andrew Tangborn, Alexandre Fournier, Ingo Wardinski, Xavier Lalanne, Julien Aubert, Elisabeth Canet, Diana Saturnino, Patrick Alken, François Civet, Brian Hamilton, Monika Korte, Jean-Michel Leger, François Bertrand, Nils Olsen, Lars Tøffner-Clausen, Erwan Thébault, Pierdavide Coïsson, Nicolas Gillet, Christopher C. Finlay, Olivier Barrois, Victoria Ridley, Mioara Mandea, Thomas Jager, A. Boness, Chandrasekharan Manoj, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), National Space Institute [Lyngby] (DTU Space), Danmarks Tekniske Universitet = Technical University of Denmark (DTU), British Geological Survey [Edinburgh], British Geological Survey (BGS), Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado [Boulder]-National Oceanic and Atmospheric Administration (NOAA), NOAA Aeronomy Laboratory, National Oceanic and Atmospheric Administration (NOAA), Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de la Terre (ISTerre), Université Joseph Fourier - Grenoble 1 (UJF)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-PRES Université de Grenoble-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Commissariat à l'énergie atomique et aux énergies alternatives - Laboratoire d'Electronique et de Technologie de l'Information (CEA-LETI), Direction de Recherche Technologique (CEA) (DRT (CEA)), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Pushkov Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagation (IZMIRAN), Russian Academy of Sciences [Moscow] (RAS), Earth and Planetary Magnetism Group [Zürich], Institut für Geophysik [Zürich], Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich)- Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), Institut de physique du globe de Strasbourg (IPGS), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institute of Geology and Geophysics [Beijing] (IGG), Chinese Academy of Sciences [Beijing] (CAS), Centre National d'Études Spatiales [Toulouse] (CNES), German Research Centre for Geosciences - Helmholtz-Centre Potsdam (GFZ), Département de Géophysique, Université des Sciences et de la Technologie Houari Boumediene = University of Sciences and Technology Houari Boumediene [Alger] (USTHB), GeoForschungsZentrum - Helmholtz-Zentrum Potsdam (GFZ), Planetary Geodynamics Laboratory [Greenbelt], NASA Goddard Space Flight Center (GSFC), School of Chemistry [Newcastle], Newcastle University [Newcastle], Centre National d’Études Spatiales [Paris] (CNES), Joint Center for Earth Systems Technology [Baltimore] (JCET), NASA Goddard Space Flight Center (GSFC)-University of Maryland [Baltimore County] (UMBC), University of Maryland System-University of Maryland System, Laboratoire de Planétologie et Géodynamique UMR6112 (LPG), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Nantes - Faculté des Sciences et des Techniques, Université de Nantes (UN)-Université de Nantes (UN)-Université d'Angers (UA), Technical University of Denmark [Lyngby] (DTU), Centre National de la Recherche Scientifique (CNRS)-Université de La Réunion (UR)-Université Paris Diderot - Paris 7 (UPD7)-IPG PARIS-Institut national des sciences de l'Univers (INSU - CNRS), Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-PRES Université de Grenoble-Institut de recherche pour le développement [IRD] : UR219-Institut national des sciences de l'Univers (INSU - CNRS)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Université Joseph Fourier - Grenoble 1 (UJF), Laboratoire d'Electronique et des Technologies de l'Information (CEA-LETI), Université Grenoble Alpes (UGA)-Direction de Recherche Technologique (CEA) (DRT (CEA)), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich)-Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology in Zürich [Zürich] (ETH Zürich), Université des Sciences et de la Technologie Houari Boumediene [Alger] (USTHB), University of Maryland [Baltimore County] (UMBC), University of Maryland System-University of Maryland System-NASA Goddard Space Flight Center (GSFC), Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Université de Strasbourg (UNISTRA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS), and Centre National de la Recherche Scientifique (CNRS)-PRES Université de Grenoble-Université Joseph Fourier - Grenoble 1 (UJF)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])
Subjects: Magnetic declination, 010504 meteorology & atmospheric sciences, Field (physics), Epoch (reference date), [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Aeronomy, Spherical harmonics, Geology, Geophysics, Geomagnetism, 010502 geochemistry & geophysics, Geodesy, 01 natural sciences, 7. Clean energy, IGRF Correspondence/Findings, Magnetic field, Secular variation, IGRF, 13. Climate action, Space and Planetary Science, Field modeling, International Geomagnetic Reference Field, 0105 earth and related environmental sciences
Abstract: International audience; The 12th generation of the International Geomagnetic Reference Field (IGRF) was adopted in December 2014 by the Working Group V-MOD appointed by the International Association of Geomagnetism and Aeronomy (IAGA). It updates the previous IGRF generation with a definitive main field model for epoch 2010.0, a main field model for epoch 2015.0, and a linear annual predictive secular variation model for 2015.0-2020.0. Here, we present the equations defining the IGRF model, provide the spherical harmonic coefficients, and provide maps of the magnetic declination, inclination, and total intensity for epoch 2015.0 and their predicted rates of change for 2015.0-2020.0. We also update the magnetic pole positions and discuss briefly the latest changes and possible future trends of the Earth's magnetic field.
Published: 2015

34. Giant impacts, heterogeneous mantle heating and a past hemispheric dynamo on Mars

Author: Hagay Amit, Gabriel Tobie, Benoit Langlais, Julien Monteux, Gaël Choblet, Institut des Sciences de la Terre (ISTerre), Université Joseph Fourier - Grenoble 1 (UJF)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-Institut national des sciences de l'Univers (INSU - CNRS)-Institut de recherche pour le développement [IRD] : UR219-PRES Université de Grenoble-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Magmas et Volcans (LMV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC), Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet [Saint-Étienne] (UJM)-Institut de Recherche pour le Développement et la société-Université Clermont Auvergne [2017-2020] (UCA [2017-2020])-Centre National de la Recherche Scientifique (CNRS)-Observatoire de Physique du Globe de Clermont-Ferrand (OPGC)
Subjects: Convection, 010504 meteorology & atmospheric sciences, Physics and Astronomy (miscellaneous), [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], [SDU.STU.PE]Sciences of the Universe [physics]/Earth Sciences/Petrography, Mars, magnetic field, 01 natural sciences, Mantle (geology), Physics::Geophysics, core-mantle boundary, Martian surface, 0103 physical sciences, Core–mantle boundary, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Martian, Astronomy and Astrophysics, Mars Exploration Program, Geophysics, dynamo, Heat flux, 13. Climate action, Space and Planetary Science, Physics::Space Physics, impact, Astrophysics::Earth and Planetary Astrophysics, Geology, Dynamo
Abstract: International audience; The martian surface exhibits a strong dichotomy in elevation, crustal thickness and magnetization between the southern and northern hemispheres. A giant impact has been proposed as an explanation for the formation of the Northern Lowlands on Mars. Such an impact probably led to strong and deep mantle heating which may have had implications on the magnetic evolution of the planet. We model the effects of such an impact on the martian magnetic field by imposing an impact induced thermal heterogeneity, and the subsequent heat flux heterogeneity, on the martian core-mantle boundary (CMB). The CMB heat flux lateral variations as well as the reduction in the mean CMB heat flux are determined by the size and geographic location of the impactor. A polar impactor leads to a north–south hemispheric magnetic dichotomy that is stronger than an east–west dichotomy created by an equatorial impactor. The amplitude of the hemispheric magnetic dichotomy is mostly controlled by the horizontal Rayleigh number RahRah which represents the vigor of the convection driven by the lateral variations of the CMB heat flux. We show that, for a given RahRah, an impact induced CMB heat flux heterogeneity is more efficient than a synthetic degree-1 CMB heat flux heterogeneity in generating strong hemispheric magnetic dichotomies. Large RahRah values are needed to get a dichotomy as strong as the observed one, favoring a reversing paleo-dynamo for Mars. Our results imply that an impactor radius of ∼1000 km could have recorded the magnetic dichotomy observed in the martian crustal field only if very rapid post-impact magma cooling took place.
Published: 2015

35. Evaluation of candidate geomagnetic field models for IGRF-12

Author: Martin Rother, Christopher C. Finlay, Vincent Lesur, Ciaran Beggan, Reyko Schachtschneider, Elisabeth Canet, Chandrasekharan Manoj, Erwan Thébault, Patrick Alken, F. J. Lowes, Benoit Langlais, Arnaud Chulliat, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), National Space Institute [Lyngby] (DTU Space), Technical University of Denmark [Lyngby] (DTU), Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado [Boulder]-National Oceanic and Atmospheric Administration (NOAA), British Geological Survey [Edinburgh], British Geological Survey (BGS), Department of Earth Sciences [Swiss Federal Institute of Technology - ETH Zürich] (D-ERDW), Eidgenössische Technische Hochschule - Swiss Federal Institute of Technology [Zürich] (ETH Zürich), German Research Centre for Geosciences - Helmholtz-Centre Potsdam (GFZ), School of Chemistry [Newcastle], and Newcastle University [Newcastle]
Subjects: Task force, [SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph], Geology, Spectral domain, Geomagnetism, Geodesy, Field (geography), Secular variation, IGRF, Earth's magnetic field, Space and Planetary Science, Physical space, Field modeling, Earth Sciences, Geological survey, International Geomagnetic Reference Field, ComputingMilieux_MISCELLANEOUS
Abstract: Background The 12th revision of the International Geomagnetic Reference Field (IGRF) was issued in December 2014 by the International Association of Geomagnetism and Aeronomy (IAGA) Division V Working Group V-MOD (http://www.ngdc.noaa.gov/IAGA/vmod/igrf.html). This revision comprises new spherical harmonic main field models for epochs 2010.0 (DGRF-2010) and 2015.0 (IGRF-2015) and predictive linear secular variation for the interval 2015.0-2020.0 (SV-2010-2015). Findings The models were derived from weighted averages of candidate models submitted by ten international teams. Teams were led by the British Geological Survey (UK), DTU Space (Denmark), ISTerre (France), IZMIRAN (Russia), NOAA/NGDC (USA), GFZ Potsdam (Germany), NASA/GSFC (USA), IPGP (France), LPG Nantes (France), and ETH Zurich (Switzerland). Each candidate model was carefully evaluated and compared to all other models and a mean model using well-defined statistical criteria in the spectral domain and maps in the physical space. These analyses were made to pinpoint both troublesome coefficients and the geographical regions where the candidate models most significantly differ. Some models showed clear deviation from other candidate models. However, a majority of the task force members appointed by IAGA thought that the differences were not sufficient to exclude models that were well documented and based on different techniques. Conclusions The task force thus voted for and applied an iterative robust estimation scheme in space. In this paper, we report on the evaluations of the candidate models and provide details of the algorithm that was used to derive the IGRF-12 product., Earth, Planets and Space, 67 (1), ISSN:1343-8832, ISSN:1880-5981
Published: 2015

36. Use of Ørsted scalar data in evaluating the pre-Ørsted main field candidate models for the IGRF 2000

Author: Benoit Langlais and Mioara Mandea
Subjects: Earth's magnetic field, Space and Planetary Science, Epoch (reference date), Position (vector), Scalar (physics), Geology, International Geomagnetic Reference Field, Geodesy, Algorithm, Field (computer science), Synthetic data, Secular variation
Abstract: For describing the main field model at the 2000.0 epoch and the secular variation over the 2000–2005 time-span, three candidate models for the International Geomagnetic Reference Field (IGRF 2000) were proposed at the beginning of 1999, called in alphabetical order IPGP00 (proposed by IPGP), IZMI00 (proposed by IZMIRAN) and USUK00 (proposed by USGS/BGS). A fourth model, IGRF95 (the updated IGRF 1995), was suggested by the Working Group chairman. The modelling methods and the data used are presented by each team elsewhere in this special issue. This study is an attempt to test these models using the total field intensity provided by the Orsted satellite, the only data available from that satellite at the time when the two tests describing here were done. The first test consists of evaluating the differences between the real and the synthetic data computed from the candidate models. The second test compares the capability of the candidate models to reduce the Backus effect, using a predictive dip-equator position and Orsted data. Both tests show that the quality of the candidate models is far from being acceptable, and, therefore, a new candidate model for the main field, using vectorial Orsted data, is required.
Published: 2000

37. Evaluation of the candidate Main Field model for IGRF 2000 derived from preliminary Ørsted data

Author: F. J. Lowes, Susan Macmillan, T. Bondar, Benoit Langlais, Mioara Mandea, and V. Golovkov
Subjects: Space and Planetary Science, Task force, Satellite data, Geology, Geodesy, Selection (genetic algorithm), Data selection, Field (computer science)
Abstract: On this occasion the selection of the IGRF for 2000 was left to a small Task Force. Before it was accepted by the Task Force as IGRF 2000, the final candidate model (a truncated version of Orsted(10c/99)) was compared with a comprehensive set of independent surface and satellite data. The method, data selection, and results of this comparison are described.
Published: 2000

38. Future Mars geophysical observatories for understanding its internal structure, rotation, and evolution

Author: Martin Knapmeyer, Tilman Spohn, Véronique Dehant, Oliver Romberg, Sami W. Asmar, Doris Breuer, Benoit Langlais, Matthias Grott, Peter L. Read, Paolo Tortora, Attilio Rivoldini, Ralf Jaumann, Susanne Vennerstrøm, Jens Biele, François Forget, Catherine L. Johnson, Philippe Lognonné, Gerald Schubert, Sue Smrekar, Antoine Mocquet, Mathieu Le Feuvre, David Mimoun, Bruce Banerdt, Stephan Ulamec, Observatoire Royal de Belgique (ORB), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Institut de Physique du Globe de Paris (IPGP), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS), Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), German Aerospace Center (DLR), DLR Institut für Planetenforschung, Institut Pierre-Simon-Laplace (IPSL), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Université Pierre et Marie Curie - Paris 6 (UPMC), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Department of Earth, Ocean and Atmospheric Sciences [Vancouver] (UBC EOAS), University of British Columbia (UBC), Université de Nantes (UN), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Département Electronique, Optronique et Signal (DEOS), Institut Supérieur de l'Aéronautique et de l'Espace (ISAE-SUPAERO), Department of Atmospheric, Oceanic and Planetary Physics [Oxford] (AOPP), University of Oxford, Department of Earth and Space Sciences [Los Angeles], University of California [Los Angeles] (UCLA), University of California (UC)-University of California (UC), V. Dehant, B. Banerdt, P. Lognonné, M. Grott, S. Asmar, J. Biele, D. Breuer, F. Forget, R. Jaumann, C. Johnson, M. Knapmeyer, B. Langlai, M. Le Feuvre, D. Mimoun, A. Mocquet, P. Read, A. Rivoldini, O. Romberg, G. Schubert, S. Smrekar, T. Spohn, P. Tortora, S. Ulamec, S. Vennerstrøm, Centre National de la Recherche Scientifique - CNRS (FRANCE), Institut de Physique du Globe de Paris - IPGP (FRANCE), Institut Supérieur de l'Aéronautique et de l'Espace - ISAE-SUPAERO (FRANCE), National Aeronautics and Space Administration - NASA (USA), Université de Paris Diderot - Paris 7 (FRANCE), Università di Bologna (ITALY), Université Pierre et Marie Curie, Paris 6 - UPMC (FRANCE), Université de La Réunion (FRANCE), California Institute of Technology - Caltech (USA), Deutsches Zentrum für Luft- und Raumfahrt - DLR (GERMANY), Ecole Normale Supérieure de Paris - ENS Paris (FRANCE), Ecole Polytechnique (FRANCE), Georges Lemaître Centre for Earth and Climate Research - TECLIM (BELGIUM), Institut national des sciences de l'Univers - INSU (FRANCE), National Space Institute (DENMARK), Royal Observatory of Belgium (BELGIUM), Planetary Science Institute (USA), Technical University of Denmark (DENMARK), Université Nantes Angers Le Mans - UNAM (FRANCE), University of California-Los Angeles - UCLA (USA), Université Catholique de Louvain - UCL (BELGIUM), University of British Columbia (CANADA), University of Oxford (UNITED KINGDOM), Jet Propulsion Laboratory - JPL (Pasadena, USA), Laboratoire de Planétologie et Géodynamique (Nantes, France), and Georges Lemaître Centre for Earth and Climate Research - TECLIM (Louvain-la-Neuve, Belgium)
Subjects: Seismometer, 010504 meteorology & atmospheric sciences, Rotation, Habitability, Mars, Interior structure, 01 natural sciences, Astrobiology, Autre, Interior Structure, Magnetic Field, 0103 physical sciences, MARS GEOPHYSICS, PLANETARY EXPLORATION, 010303 astronomy & astrophysics, Geothermal gradient, Seismology, 0105 earth and related environmental sciences, Radio Science, Physics, MARS ROTATION, Atmosphere, Geodetic datum, Biosphere, Astronomy and Astrophysics, Heat Flow, Mars Exploration Program, Geophysics, Planetary science, Magnetic field, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Terrestrial planet, Heat flow
Abstract: Our fundamental understanding of the interior of the Earth comes from seismology, geodesy, geochemistry, geomagnetism, geothermal studies, and petrology. For the Earth, measurements in those disciplines of geophysics have revealed the basic internal layering of the Earth, its dynamical regime, its thermal structure, its gross compositional stratification, as well as significant lateral variations in these quantities. Planetary interiors not only record evidence of conditions of planetary accretion and differentiation, they exert significant control on surface environments. We present recent advances in possible in-situ investigations of the interior of Mars, experiments and strategies that can provide unique and critical information about the fundamental processes of terrestrial planet formation and evolution. Such investigations applied on Mars have been ranked as a high priority in virtually every set of European, US and international high-level planetary science recommendations for the past 30 years. New seismological methods and approaches based on the cross-correlation of seismic noise by two seismic stations/landers on the surface of Mars and on joint seismic/orbiter detection of meteorite impacts, as well as the improvement of the performance of Very Broad-Band (VBB) seismometers have made it possible to secure a rich scientific return with only two simultaneously recording stations. In parallel, use of interferometric methods based on two Earth–Mars radio links simultaneously from landers tracked from Earth has increased the precision of radio science experiments by one order of magnitude. Magnetometer and heat flow measurements will complement seismic and geodetic data in order to obtain the best information on the interior of Mars. In addition to studying the present structure and dynamics of Mars, these measurements will provide important constraints for the astrobiology of Mars by helping to understand why Mars failed to sustain a magnetic field, by helping to understand the planet’s climate evolution, and by providing a limit for the energy available to the chemoautotrophic biosphere through a measurement of the surface heat flow. The landers of the mission will also provide meteorological stations to monitor the climate and obtain new measurements in the atmospheric boundary layer.
Published: 2012

39. A chronology of early Mars climatic evolution from impact crater degradation

Author: Benoit Langlais, Susan J. Conway, Solmaz Adeli, Nicolas Mangold, and Veronique Ansan
Subjects: Atmospheric Science, 010504 meteorology & atmospheric sciences, Amazonian, Geochemistry, Soil Science, Fluvial, Aquatic Science, Oceanography, 01 natural sciences, Impact crater, Geochemistry and Petrology, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), Ejecta, 010303 astronomy & astrophysics, Geomorphology, 0105 earth and related environmental sciences, Earth-Surface Processes, Water Science and Technology, Martian, geography, geography.geographical_feature_category, Ecology, Alluvial fan, Noachian, Paleontology, Forestry, 15. Life on land, Geophysics, 13. Climate action, Space and Planetary Science, Hesperian, Geology
Abstract: [1] The degradation of impact craters provides a powerful tool to analyze surface processes in the Martian past. Previous studies concluded that large impact craters (20–200 km in diameter) were strongly degraded by fluvial erosion during early Martian history. Our goal is to study the progression of crater degradation through time with a particular emphasis on the craters with alluvial fans and on the relative chronology of these craters. The geometric properties of 283 craters of >20 km in diameter were analyzed in two highlands of Mars, north of Hellas Planitia, and south of Margaritifer Terra, both known to contain craters with alluvial fans. Three classes were defined from morphology: strongly degraded craters with fluvial landforms and without ejecta (type I), gently degraded craters with fluvial landforms and preserved ejecta (type II), and fresh craters with ejecta and no fluvial landforms (type III). Our main result is that the type II craters that present alluvial fans have characteristics closer to fresh craters (type III) than degraded craters (type I). The distinctive degradation characteristics of these classes allowed us to determine a temporal distribution: Type I craters were formed and degraded between ∼4 Gyr and ∼3.7 Gyr and type II craters with alluvial fans were formed between Early Hesperian and Early Amazonian (∼3.7 to ∼3.3 Gyr). This chronology is corroborated by crosscutting relationships of individual type II craters, which postdate Late Noachian valley networks. The sharp transition at ∼3.7 Gyr suggests a quick change in climatic conditions that could correspond to the cessation of the dynamo.
Published: 2012

40. Predicted and observed magnetic signatures of Martian (de)magnetized impact craters

Author: Erwan Thébault, Benoit Langlais, Université de Nantes (UN), Institut de Physique du Globe de Paris (IPGP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Institut de Physique du Globe de Paris (IPG Paris)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010504 meteorology & atmospheric sciences, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Mars, interior, 01 natural sciences, Astrobiology, Physics::Geophysics, Magnetization, Altitude, Impact crater, 0103 physical sciences, surface, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Martian, Impact processes, Demagnetizing field, Astronomy and Astrophysics, Mars Exploration Program, Geophysics, Magnetic field, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Magnetic fields, Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics, Geology, Dynamo
Abstract: The current morphology of the martian lithospheric magnetic field results from magnetization and demagnetization processes, both of which shaped the planet. The largest martian impact craters, Hellas, Argyre, Isidis and Utopia, are not associated with intense magnetic fields at spacecraft altitude. This is usually interpreted as locally non- or de-magnetized areas, as large impactors may have reset the magnetization of the pre-impact material. We study the effects of impacts on the magnetic field. First, a careful analysis is performed to compute the impact demagnetization effects. We assume that the pre-impact lithosphere acquired its magnetization while cooling in the presence of a global, centered and mainly dipolar magnetic field, and that the subsequent demagnetization is restricted to the excavation area created by large craters, between 50- and 500-km diameter. Depth-to-diameter ratio of the transient craters is set to 0.1, consistent with observed telluric bodies. Associated magnetic field is computed between 100- and 500-km altitude. For a single-impact event, the maximum magnetic field anomaly associated with a crater located over the magnetic pole is maximum above the crater. A 200-km diameter crater presents a close-to-1-nT magnetic field anomaly at 400-km altitude, while a 100-km diameter crater has a similar signature at 200-km altitude. Second, we statistically study the 400-km altitude Mars Global Surveyor magnetic measurements modelled locally over the visible impact craters. This approach offers a local estimate of the confidence to which the magnetic field can be computed from real measurements. We conclude that currently craters down to a diameter of 200 km can be characterized. There is a slight anti-correlation of −0.23 between magnetic field intensity and impact crater diameters, although we show that this result may be fortuitous. A complete low-altitude magnetic field mapping is needed. New data will allow predicted weak anomalies above craters to be better characterized, and will bring new constraints on the timing of the martian dynamo and on Mars’ evolution.
Published: 2011

41. Crustal magnetic fields of terrestrial planets

Author: Benoit Langlais, Vincent Lesur, Mioara Mandea, Michael E. Purucker, John E. P. Connerney, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), and Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010504 meteorology & atmospheric sciences, Astronomy, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Astronomy and Astrophysics, 550 - Earth sciences, Geophysics, 010502 geochemistry & geophysics, 01 natural sciences, Outer core, L-shell, Physics::Geophysics, Magnetic field of the Moon, Earth's magnetic field, Planetary science, 13. Climate action, Space and Planetary Science, Physics::Space Physics, Terrestrial planet, Astrophysics::Earth and Planetary Astrophysics, Magnetic anomaly, Mercury's magnetic field, Geology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences
Abstract: Magnetic field measurements are very valuable, as they provide constraints on the interior of the telluric planets and Moon. The Earth possesses a planetary scale magnetic field, generated in the conductive and convective outer core. This global magnetic field is superimposed on the magnetic field generated by the rocks of the crust, of induced (i.e. aligned on the current main field) or remanent (i.e. aligned on the past magnetic field). The crustal magnetic field on the Earth is very small scale, reflecting the processes (internal or external) that shaped the Earth. At spacecraft altitude, it reaches an amplitude of about 20 nT. Mars, on the contrary, lacks today a magnetic field of core origin. Instead, there is only a remanent magnetic field, which is one to two orders of magnitude larger than the terrestrial one at spacecraft altitude. The heterogeneous distribution of the Martian magnetic anomalies reflects the processes that built the Martian crust, dominated by igneous and cratering processes. These latter processes seem to be the driving ones in building the lunar magnetic field. As Mars, the Moon has no core-generated magnetic field. Crustal magnetic features are very weak, reaching only 30 nT at 30-km altitude. Their distribution is heterogeneous too, but the most intense anomalies are located at the antipodes of the largest impact basins. The picture is completed with Mercury, which seems to possess an Earth-like, global magnetic field, which however is weaker than expected. Magnetic exploration of Mercury is underway, and will possibly allow the Hermean crustal field to be characterized. This paper presents recent advances in our understanding and interpretation of the crustal magnetic field of the telluric planets and Moon.
Published: 2010

42. Magnetic field microscopy of rock samples using a giant magnetoresistance-based scanning magnetometer

Author: Fatim Hankard, Benoit Langlais, Yoann Quesnel, Pierre Rochette, Claude Fermon, Suzanne A. McEnroe, Myriam Pannetier-Lecoeur, and Jérôme Gattacceca
Subjects: Scanning Hall probe microscope, Microscope, 010504 meteorology & atmospheric sciences, business.industry, Magnetometer, Giant magnetoresistance, 010502 geochemistry & geophysics, 01 natural sciences, law.invention, Magnetic field, Geophysics, Optics, Nuclear magnetic resonance, Geochemistry and Petrology, law, Microscopy, Magnetic force microscope, business, Geology, Noise (radio), 0105 earth and related environmental sciences
Abstract: [1] We have developed a new scanning magnetic microscope to image with micrometric resolution magnetic fields originating from room temperature polished samples. This microscope is based on a giant magnetoresistance (GMR) sensor working at room temperature. These magnetic sensors are sensitive to the in-plane components of the magnetic field. The size of the sensing element is 9 μm × 36 μm. The noise of the GMR sensor is dominated by a low-frequency 1/f noise. The field equivalent noise of the sensors is 10 nT at 1Hz and decreases to 0.3 nT above 1 kHz for a 1 mA sensing current. The spatial resolution of the system is ∼20 μm, and its peak-to-peak noise during operation is ∼250 nT. Its high spatial resolution and a minimum sensor-to-sample distance of 30 μm compensate for its rather moderate field sensitivity. This room temperature small-sized and rugged magnetic microscope appears as a powerful instrument for small-scale rock magnetic investigations.
Published: 2009

43. Mars Environment and Magnetic Orbiter Scientific and Measurement Objectives

Author: Miguel Lopez-Valverde, François Leblanc, Benoit Langlais, Michel Menvielle, A. Pais, Stephen R. Lewis, Andrew J. Coates, T. Fouchet, Helmut Lammer, François Forget, Eric Chassefière, Martin Paetzold, Doris Breuer, Pascal Tarits, Peter L. Read, Susanne Vennerstrøm, Christophe Sotin, Véronique Dehant, S. Barabash, Mioara Mandea, PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire de Paris - Site de Paris (OP), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Swedish Institute of Space Physics [Uppsala] (IRF), Deutsches Zentrum für Luft- und Raumfahrt (DLR), Department of Space and Climate Physics [UCL London], Mullard Space Science Laboratory (MSSL), University College of London [London] (UCL)-University College of London [London] (UCL), Royal Observatory of Belgium [Brussels] (ROB), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Space Research Institute of Austrian Academy of Sciences (IWF), Austrian Academy of Sciences (OeAW), Department of Physics and Astronomy [Milton Keynes], The Open University [Milton Keynes] (OU), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), HELIOS - LATMOS, Department of Physics [Coimbra], University of Coimbra [Portugal] (UC), Universität zu Köln, Université de Brest (UBO), National Space Institute [Lyngby] (DTU Space), Technical University of Denmark [Lyngby] (DTU), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Universität zu Köln = University of Cologne, Danmarks Tekniske Universitet = Technical University of Denmark (DTU), and 2.3 Earth's Magnetic Field, 2.0 Physics of the Earth, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum
Subjects: Time Factors, Cosmic Vision, Extraterrestrial Environment, 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Mars, 550 - Earth sciences, 01 natural sciences, Astrobiology, law.invention, Atmosphere, Magnetics, Orbiter, law, Planet, Exobiology, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, Computer Simulation, 010303 astronomy & astrophysics, Physics::Atmospheric and Oceanic Physics, 0105 earth and related environmental sciences, Martian, [SDU.OCEAN]Sciences of the Universe [physics]/Ocean, Atmosphere, Altitude, Astrophysics::Instrumentation and Methods for Astrophysics, Mars Exploration Program, Space Flight, Satellite Communications, Agricultural and Biological Sciences (miscellaneous), Solar wind, 13. Climate action, Space and Planetary Science, Physics::Space Physics, Environmental science, Planetary Evolution, Astrophysics::Earth and Planetary Astrophysics, Evolution, Planetary
Abstract: International audience; In this paper, we summarize our present understanding of Mars' atmosphere, magnetic field, and surface and address past evolution of these features. Key scientific questions concerning Mars' surface, atmosphere, and magnetic field, along with the planet's interaction with solar wind, are discussed. We also define what key parameters and measurements should be performed and the main characteristics of a martian mission that would help to provide answers to these questions.Such a mission—Mars Environment and Magnetic Orbiter (MEMO)—was proposed as an answer to the Cosmic Vision Call of Opportunity as an M-class mission (corresponding to a total European Space Agency cost of less than 300 M€). MEMO was designed to study the strong interconnection between the planetary interior, atmosphere, and solar conditions, which is essential to our understanding of planetary evolution, the appearance of life, and its sustainability.The MEMO main platform combined remote sensing and in situ measurements of the atmosphere and the magnetic field during regular incursions into the martian upper atmosphere. The micro-satellite was designed to perform simultaneous in situ solar wind measurements. MEMO was defined to conduct:• Four-dimensional mapping of the martian atmosphere from the surface up to 120 km by measuring wind, temperature, water, and composition, all of which would provide a complete view of the martian climate and photochemical system;• Mapping of the low-altitude magnetic field with unprecedented geographical, altitude, local time, and seasonal resolutions;• A characterization of the simultaneous responses of the atmosphere, magnetic field, and near-Mars space to solar variability by means of in situ atmospheric and solar wind measurements.
Published: 2009

44. Mars environment and magnetic orbiter model payload

Author: J.E. Walhund, A. Pais, Pascal Tarits, S. Barabash, François Leblanc, T. Ott, Mioara Mandea, Stephen R. Lewis, Benoit Langlais, Helmut Lammer, Jean-Gabriel Trotignon, Eric Chassefière, J.G.M. Merayo, Martin Paetzold, Peter L. Read, Henri Rème, Gabriele Cremonese, François Forget, Andrew J. Coates, Susanne Vennerstrøm, Christophe Sotin, Michel Menvielle, Véronique Dehant, Miguel Lopez-Valverde, Doris Breuer, T. Fouchet, Graziella Branduardi-Raymont, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Swedish Institute of Space Physics [Uppsala] (IRF), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Mullard Space Science Laboratory (MSSL), University College of London [London] (UCL), Royal Observatory of Belgium [Brussels] (ROB), Laboratoire de Météorologie Dynamique (UMR 8539) (LMD), Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS)-École des Ponts ParisTech (ENPC)-École polytechnique (X)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Space Research Institute of Austrian Academy of Sciences (IWF), Austrian Academy of Sciences (OeAW), Department of Physics and Astronomy [Milton Keynes], The Open University [Milton Keynes] (OU), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), GeoForschungsZentrum - Helmholtz-Zentrum Potsdam (GFZ), HELIOS - LATMOS, Department of Physics [Coimbra], University of Coimbra [Portugal] (UC), Universität zu Köln, Department of Atmospheric, Oceanic and Planetary Physics [Oxford] (AOPP), University of Oxford [Oxford], Institut Universitaire Européen de la Mer (IUEM), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), National Space Institute [Lyngby] (DTU Space), Technical University of Denmark [Lyngby] (DTU), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Swedish Space Corporation (SSC), Centre d'étude spatiale des rayonnements (CESR), Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées, Laboratoire de physique et chimie de l'environnement (LPCE), Université d'Orléans (UO)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Planétologie et Géodynamique de Nantes ( LPGN ), Université de Nantes ( UN ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire d'études spatiales et d'instrumentation en astrophysique ( LESIA ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire de Paris-Université Paris Diderot - Paris 7 ( UPD7 ) -Centre National de la Recherche Scientifique ( CNRS ), Swedish Institute of Space Physics [Uppsala] ( IRF ), Deutsches Zentrum für Luft- und Raumfahrt [Berlin] ( DLR ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Mullard Space Science Laboratory ( MSSL ), University College of London [London] ( UCL ), Royal Observatory of Belgium [Brussels], Laboratoire de Météorologie Dynamique (UMR 8539) ( LMD ), Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -École polytechnique ( X ) -École des Ponts ParisTech ( ENPC ) -Centre National de la Recherche Scientifique ( CNRS ) -Département des Géosciences - ENS Paris, École normale supérieure - Paris ( ENS Paris ) -École normale supérieure - Paris ( ENS Paris ), Space Research Institute of Austrian Academy of Sciences ( IWF ), Austrian Academy of Sciences ( OeAW ), The Open University [Milton Keynes] ( OU ), Instituto de Astrofísica de Andalucía ( IAA ), Consejo Superior de Investigaciones Científicas [Spain] ( CSIC ), GeoForschungsZentrum - Helmholtz-Zentrum Potsdam ( GFZ ), HEPPI - LATMOS, University of Coimbra [Portugal] ( UC ), Department of Atmospheric, Oceanic and Planetary Physics [Oxford] ( AOPP ), Institut Universitaire Européen de la Mer ( IUEM ), Institut de Recherche pour le Développement ( IRD ) -Université de Brest ( UBO ) -Centre National de la Recherche Scientifique ( CNRS ), National Space Institute [Lyngby] ( DTU Space ), Technical University of Denmark [Lyngby] ( DTU ), INAF - Osservatorio Astronomico di Padova ( OAPD ), Istituto Nazionale di Astrofisica ( INAF ), Swedish Space Corporation ( SSC ), Centre d'étude spatiale des rayonnements ( CESR ), Université Paul Sabatier - Toulouse 3 ( UPS ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Observatoire Midi-Pyrénées ( OMP ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de physique et chimie de l'environnement ( LPCE ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Université d'Orléans ( UO ) -Centre National de la Recherche Scientifique ( CNRS ), 2.3 Earth's Magnetic Field, 2.0 Physics of the Earth, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum, Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-École des Ponts ParisTech (ENPC)-Centre National de la Recherche Scientifique (CNRS)-Département des Géosciences - ENS Paris, École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL), Universität zu Köln = University of Cologne, University of Oxford, Danmarks Tekniske Universitet = Technical University of Denmark (DTU), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), and Institut national des sciences de l'Univers (INSU - CNRS)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Solar System, Cosmic Vision, 010504 meteorology & atmospheric sciences, [PHYS.ASTR.EP]Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], planetary interior, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], 550 - Earth sciences, 01 natural sciences, 7. Clean energy, law.invention, Atmosphere, Orbiter, law, 0103 physical sciences, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Remote sensing, Orbital elements, Physics, Astrophysics::Instrumentation and Methods for Astrophysics, Astronomy and Astrophysics, Space vehicles, Mars Exploration Program, M-class mission, planetary evolution, solar conditions, [ SDU.ASTR.EP ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Solar wind, [ PHYS.ASTR.EP ] Physics [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], 13. Climate action, Space and Planetary Science, MEMO, Magnetic fields, atmosphere, Physics::Space Physics, Solar-terrestrial relations, Mars Environment and Magnetic Orbiter, Timekeeping on Mars, Astrophysics::Earth and Planetary Astrophysics, Planets and satellites, Solar system
Abstract: International audience; Mars Environment and Magnetic Orbiter was proposed as an answer to the Cosmic Vision Call of Opportunity as a M-class mission. The MEMO mission is designed to study the strong interconnections between the planetary interior, atmosphere and solar conditions essential to understand planetary evolution, the appearance of life and its sustainability. MEMO provides a high-resolution, complete, mapping of the magnetic field (below an altitude of about 250 km), with an yet unachieved full global coverage. This is combined with an in situ characterization of the high atmosphere and remote sensing of the middle and lower atmospheres, with an unmatched accuracy. These measurements are completed by an improved detection of the gravity field signatures associated with carbon dioxide cycle and to the tidal deformation. In addition the solar wind, solar EUV/UV and energetic particle fluxes are simultaneously and continuously monitored. The challenging scientific objectives of the MEMO mission proposal are fulfilled with the appropriate scientific instruments and orbit strategy. MEMO is composed of a main platform, placed on a elliptical (130 × 1,000 km), non polar (77° inclination) orbit, and of an independent, higher apoapsis (10,000 km) and low periapsis (300 km) micro-satellite. These orbital parameters are designed so that the scientific return of MEMO is maximized, in terms of measurement altitude, local time, season and geographical coverage. MEMO carry several suites of instruments, made of an ‘exospheric-upper atmosphere’ package, a ‘magnetic field’ package, and a ‘low-middle atmosphere’ package. Nominal mission duration is one Martian year.
Published: 2009

45. Simple models for the Beattie Magnetic Anomaly in South Africa

Author: Benoit Langlais, Vincent Lesur, Armand Galdeano, Jacek Stankiewicz, Mioara Mandea, Ute Weckmann, Christophe Sotin, Yoann Quesnel, Oliver Ritter, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), and Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Offset (computer science), 010504 meteorology & atmospheric sciences, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, 550 - Earth sciences, Inversion (meteorology), Crust, Geophysics, 010502 geochemistry & geophysics, 01 natural sciences, Magnetization, Magnetotellurics, SPHERES, Institut für Geowissenschaften, Shear zone, Magnetic anomaly, ComputingMilieux_MISCELLANEOUS, Geology, Seismology, 0105 earth and related environmental sciences, Earth-Surface Processes
Abstract: The origin of the approximately 1000 km-long Beattie Magnetic Anomaly (BMA) in South Africa remains unclear and contentious. Key issues include the width, depth and magnetization of its source. In this study, we use uniformly magnetized spheres, prisms and cylinders to provide the simplest possible models which predict the 1 km-altitude aeromagnetic measurements along a profile across the BMA. The source parameters are adjusted by forward modeling. In case of a sphere, an inversion technique is applied to refine the parameters. Our results suggest that two similarly magnetized and adjacent sources, with a vertical offset, can explain the observed magnetic anomaly. The best fitting model corresponds to two highly-magnetized (> 5 A m − 1 ) sheet-like prisms, extending from 9 to 12 km depth, and from 13 to 18 km depth, respectively, and with a total width reaching 80 km. Other less-preferred models show thicker and deeper magnetized volumes. Associated magnetizations seem to be mostly induced, although a weak remanent component is required to improve the fit. We also compare our results with the interpretation of independent magnetotelluric and seismic experiments along the same profile. It suggests that the geological sources for the BMA are mostly located in the middle crust and may be displaced by a shear zone or a fault. Contrary to previous models suggesting a serpentinized sliver of paleo-oceanic crust within the Natal–Namaqua Mobile Belt, we propose that granulite-facies mid-crustal rocks within this belt may cause the BMA.
Published: 2009

46. Serpentinization of the martian crust during Noachian

Author: Mioara Mandea, Benoit Langlais, Yoann Quesnel, Jérôme Dyment, Christophe Sotin, Simona Costin, Matthias Gottschalk, 2.3 Earth's Magnetic Field, 2.0 Physics of the Earth, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), and Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: 010504 meteorology & atmospheric sciences, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, 550 - Earth sciences, 01 natural sciences, Gravity anomaly, Physics::Geophysics, Geochemistry and Petrology, Lithosphere, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), Magnetic anomaly, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, Physics::Atmospheric and Oceanic Physics, 0105 earth and related environmental sciences, Martian, Noachian, Crust, Mars Exploration Program, Geophysics, 13. Climate action, Space and Planetary Science, Astrophysics::Earth and Planetary Astrophysics, Geology, Dynamo
Abstract: This paper proposes a model of serpentinization of the Southern martian crust that may explain the topographic dichotomy, the absence of an associated free-air gravity anomaly and the presence of strong magnetic anomalies in the Southern Hemisphere. The thermodynamical conditions for serpentinization were likely met in the lithosphere during the Noachian period. This process may have decreased the density in the Southern crust and created the topographic dichotomy. Different reactions of serpentinization that can form magnetite have been considered. Assuming an intense magnetic field (core dynamo), we obtain chemical remanent magnetizations that are in the order of the estimates deduced from martian magnetic anomaly studies. The pertinence and the implications of our model concerning the early thermal evolution of Mars are discussed, with emphasis on the intensity of the paleo-magnetic field.
Published: 2009

47. The Past Martian Dynamo

Author: Benoit Langlais, H. Amit, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), and Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Martian, Multidisciplinary, 010504 meteorology & atmospheric sciences, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, Mars Exploration Program, 010502 geochemistry & geophysics, 01 natural sciences, Physics::Geophysics, Astrobiology, Magnetic field, Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics, Southern Hemisphere, Physics::Atmospheric and Oceanic Physics, Geology, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Dynamo
Abstract: Numerical dynamo modeling studies may explain the observation that strong magnetic fields are only found in Mars' southern hemisphere.
Published: 2008

48. The origin of Mercury's internal magnetic field

Author: Johannes Wicht, Mioara Mandea, Masaki Matsushima, Benoit Langlais, Ulrich R. Christensen, Futoshi Takahashi, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and 2.3 Earth's Magnetic Field, 2.0 Physics of the Earth, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum
Subjects: Convection, Physics, 010504 meteorology & atmospheric sciences, Inner core, [SDU.STU]Sciences of the Universe [physics]/Earth Sciences, 550 - Earth sciences, Mechanics, 010502 geochemistry & geophysics, 01 natural sciences, Physics::Geophysics, Magnetic field, Dipole, symbols.namesake, Amplitude, 13. Climate action, symbols, Mercury's magnetic field, Lorentz force, 0105 earth and related environmental sciences, Dynamo
Abstract: Mariner 10 measurements proved the existence of a large-scale internal magnetic field on Mercury. The observed field amplitude, however, is too weak to be compatible with typical convective planetary dynamos. The Lorentz force based on an extrapolation of Mariner 10 data to the dynamo region is 10−4 times smaller than the Coriolis force. This is at odds with the idea that planetary dynamos are thought to work in the so-called magnetostrophic regime, where Coriolis force and Lorentz force should be of comparable magnitude. Recent convective dynamo simulations reviewed here seem to resolve this caveat. We show that the available convective power indeed suffices to drive a magnetostrophic dynamo even when the heat flow though Mercury’s core–mantle boundary is subadiabatic, as suggested by thermal evolution models. Two possible causes are analyzed that could explain why the observations do not reflect a stronger internal field. First, toroidal magnetic fields can be strong but are confined to the conductive core, and second, the observations do not resolve potentially strong small-scale contributions. We review different dynamo simulations that promote either or both effects by (1) strongly driving convection, (2) assuming a particularly small inner core, or (3) assuming a very large inner core. These models still fall somewhat short of explaining the low amplitude of Mariner 10 observations, but the incorporation of an additional effect helps to reach this goal: The subadiabatic heat flow through Mercury’s core–mantle boundary may cause the outer part of the core to be stably stratified, which would largely exclude convective motions in this region. The magnetic field, which is small scale, strong, and very time dependent in the lower convective part of the core, must diffuse through the stagnant layer. Here, the electromagnetic skin effect filters out the more rapidly varying high-order contributions and mainly leaves behind the weaker and slower varying dipole and quadrupole components (Christensen in Nature 444:1056–1058, 2006). Messenger and BepiColombo data will allow us to discriminate between the various models in terms of the magnetic fields spatial structure, its degree of axisymmetry, and its secular variation.
Published: 2008

49. The origin of Mercury's internal magnetic field

Author: Mioara Mandea, Benoit Langlais, Ulrich R. Christensen, Masaki Matsushima, Johannes Wicht, Futoshi Takahashi, Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and 2.3 Earth's Magnetic Field, 2.0 Physics of the Earth, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum
Subjects: Convection, Physics, 010504 meteorology & atmospheric sciences, Inner core, Astronomy and Astrophysics, 550 - Earth sciences, Mechanics, 010502 geochemistry & geophysics, 01 natural sciences, Physics::Geophysics, Magnetic field, symbols.namesake, Classical mechanics, Amplitude, [SDU.STU.PL]Sciences of the Universe [physics]/Earth Sciences/Planetology, 13. Climate action, Space and Planetary Science, Heat transfer, symbols, Mercury's magnetic field, Lorentz force, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Dynamo
Abstract: Mariner 10 measurements proved the existence of a large-scale internal magnetic field on Mercury. The observed field amplitude, however, is too weak to be compatible with typical convective planetary dynamos. The Lorentz force based on an extrapolation of Mariner 10 data to the dynamo region is 10−4 times smaller than the Coriolis force. This is at odds with the idea that planetary dynamos are thought to work in the so-called magnetostrophic regime, where Coriolis force and Lorentz force should be of comparable magnitude. Recent convective dynamo simulations reviewed here seem to resolve this caveat. We show that the available convective power indeed suffices to drive a magnetostrophic dynamo even when the heat flow though Mercury’s core–mantle boundary is subadiabatic, as suggested by thermal evolution models. Two possible causes are analyzed that could explain why the observations do not reflect a stronger internal field. First, toroidal magnetic fields can be strong but are confined to the conductive core, and second, the observations do not resolve potentially strong small-scale contributions. We review different dynamo simulations that promote either or both effects by (1) strongly driving convection, (2) assuming a particularly small inner core, or (3) assuming a very large inner core. These models still fall somewhat short of explaining the low amplitude of Mariner 10 observations, but the incorporation of an additional effect helps to reach this goal: The subadiabatic heat flow through Mercury’s core–mantle boundary may cause the outer part of the core to be stably stratified, which would largely exclude convective motions in this region. The magnetic field, which is small scale, strong, and very time dependent in the lower convective part of the core, must diffuse through the stagnant layer. Here, the electromagnetic skin effect filters out the more rapidly varying high-order contributions and mainly leaves behind the weaker and slower varying dipole and quadrupole components (Christensen in Nature 444:1056–1058, 2006). Messenger and BepiColombo data will allow us to discriminate between the various models in terms of the magnetic fields spatial structure, its degree of axisymmetry, and its secular variation.
Published: 2007

50. Crustal magnetic field of Mars

Author: Michael E. Purucker, Mioara Mandea, and Benoit Langlais
Subjects: Atmospheric Science, 010504 meteorology & atmospheric sciences, Soil Science, Aquatic Science, Oceanography, 01 natural sciences, L-shell, Magnetization, Geochemistry and Petrology, 0103 physical sciences, Earth and Planetary Sciences (miscellaneous), Magnetic anomaly, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Earth-Surface Processes, Water Science and Technology, Physics, Ecology, Demagnetizing field, Paleontology, Forestry, Geophysics, Dipole model of the Earth's magnetic field, Mars Exploration Program, Magnetic field, Computational physics, Dipole, 13. Climate action, Space and Planetary Science
Abstract: [1] The equivalent source dipole technique is used to model the three components of the Martian lithospheric magnetic field. We use magnetic field measurements made on board the Mars Global Surveyor spacecraft. Different input dipole meshes are presented and evaluated. Because there is no global, Earth-like, inducing magnetic field, the magnetization directions are solved for together with the magnetization intensity. A first class of models is computed using either low-altitude or high-altitude measurements, giving some statistical information about the depth of the dipoles. Then, a second class of models is derived on the basis of measurements made between 80 and 430 km altitude. The 4840 dipoles are placed 20 km below the surface, with a mean spacing of 2.92° (173 km). Residual rms values between observations and predictions are as low as 15 nT for the total field, with associated correlation coefficient equal to 0.97. The resulting model is used to predict the magnetic field at 200-km constant altitude. We present the maps of the magnetic field and of the magnetization. Downward continuation of a spherical harmonic model derived from our equivalent source solution suggests that intermediate-scale lithospheric fields at the surface probably exceed 5000 nT. Given an assumed 40-km-thick magnetized layer, with a mean volume per dipole equal to 3.6.106 km3, the magnetization components range between ±12 A/m. We also present apparent correlations between some impact craters (≥300-km diameter) and magnetization contrasts. Finally, we discuss the implications of the directional information and possible magnetic carriers.
Published: 2004

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