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1. Gesundheitskompetenz von Mitarbeitenden

Author: N. Kohls and C. Güttler
Subjects: Gynecology, 03 medical and health sciences, medicine.medical_specialty, 0302 clinical medicine, Political science, Public Health, Environmental and Occupational Health, medicine, 030212 general & internal medicine, 030210 environmental & occupational health
Abstract: Zusammenfassung Hintergrund Um mit den zunehmenden Belastungen und Herausforderungen umgehen zu können, wird Gesundheitskompetenz (GK) im Alltag und Arbeitskontext immer wichtiger. Ziel der Arbeit Das Ziel dieser Arbeit ist es, eine Analyse der selbsteingeschätzten GK der Mitarbeitenden eines Unternehmens der verarbeitenden Metallindustrie durchzuführen und auf deren Grundlage Handlungsempfehlungen zur Stärkung der GK herauszustellen. Material und Methoden In dieser Arbeit wurde die GK der Mitarbeitenden mit der Kurzform des European Health Literacy Questionnaire (HLS-EU-Q16) sowie Angaben zum soziodemographischen Hintergrund, Gesundheitsverhalten, Gesundheitszustand und Wohlbefinden erhoben und analysiert. Mit Hilfe einer Online- und Paper-pencil-Befragung sollte in dieser quantitativen Erhebung eine repräsentative Stichprobe aus der Gesamtbelegschaft generiert werden. Ergebnisse Die meisten Mitarbeitenden der 458 teilgenommenen Personen verfügten über eine ausreichende GK (39,7 %). Mehr als die Hälfte der Mitarbeitenden (60,3 %) wies jedoch eine problematische oder inadäquate GK auf. Es konnten Zusammenhänge zwischen der GK und dem Wohlbefinden, Gesundheitszustand und verschiedenen gesundheitsförderlichen Verhaltensweisen festgestellt werden. Diskussion Die Ergebnisse verdeutlichen, dass ein Handlungsbedarf zur Stärkung der GK von Beschäftigten besteht. Durch die genannten Handlungsempfehlungen kann diese erzielt werden. Um deren Wirksamkeit zu überprüfen, sollte eine Folgeerhebung als Vergleich dienen. Weiterhin benötigt es einer dauerhaften Sensibilisierung aller Führungskräfte und Mitarbeitenden für die Förderung der GK.
Published: 2021
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2. Cometary dust analogues for physics experiments

Author: A Lethuillier, C Feller, E Kaufmann, P Becerra, N Hänni, R Diethelm, C Kreuzig, B Gundlach, J Blum, A Pommerol, G Kargl, S Laddha, K Denisova, E Kührt, H L Capelo, D Haack, X Zhang, J Knollenberg, N S Molinski, T Gilke, H Sierks, P Tiefenbacher, C Güttler, K A Otto, D Bischoff, M Schweighart, A Hagermann, and N Jäggi
Subjects: Earth and Planetary Astrophysics (astro-ph.EP), laboratory experiments, Space and Planetary Science, FOS: Physical sciences, Astronomy and Astrophysics, CoPhyLab, comets, Astrophysics - Instrumentation and Methods for Astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), dust analogue, Astrophysics - Earth and Planetary Astrophysics
Abstract: The CoPhyLab (Cometary Physics Laboratory) project is designed to study the physics of comets through a series of earth-based experiments. For these experiments, a dust analogue was created with physical properties comparable to those of the non-volatile dust found on comets. This ‘CoPhyLab dust’ is planned to be mixed with water and CO2 ice and placed under cometary conditions in vacuum chambers to study the physical processes taking place on the nuclei of comets. In order to develop this dust analogue, we mixed two components representative for the non-volatile materials present in cometary nuclei. We chose silica dust as a representative for the mineral phase and charcoal for the organic phase, which also acts as a darkening agent. In this paper, we provide an overview of known cometary analogues before presenting measurements of eight physical properties of different mixtures of the two materials and a comparison of these measurements with known cometary values. The physical properties of interest are particle size, density, gas permeability, spectrophotometry, and mechanical, thermal, and electrical properties. We found that the analogue dust that matches the highest number of physical properties of cometary materials consists of a mixture of either 60 per cent/40 per cent or 70 per cent/30 per cent of silica dust/charcoal by mass. These best-fit dust analogue will be used in future CoPhyLab experiments.
Published: 2021

3. Long-term measurements of the erosion and accretion of dust deposits on comet 67P/Churyumov-Gerasimenko with the OSIRIS instrument

Author: Cecilia Tubiana, Giampiero Naletto, G. Cremonese, P. Cambianica, C. Güttler, Alice Lucchetti, Matteo Massironi, E. Frattin, Luca Penasa, Marco Fulle, Maurizio Pajola, Emanuele Simioni, and Holger Sierks
Subjects: Physics, 010504 meteorology & atmospheric sciences, biology, Comet, Astronomy, comets: individual: 67P/Churyumov-Gerasimenko, Astronomy and Astrophysics, biology.organism_classification, 01 natural sciences, methods: data analysis, Accretion (astrophysics), Term (time), methods: numerical, Space and Planetary Science, 0103 physical sciences, Erosion, Osiris, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: We monitor the seasonal erosion and accretion of dust deposits in the Imhotep, Hatmehit, and Ma’at regions of comet 67P/Churyumov–Gerasimenko with OSIRIS Narrow Angle Camera images. The vertical accuracy of such measurements is 0.2 m and the spatial scale of the images we used is lower than 0.60 m pixel−1. We calculate the height of 21 boulders by applying a tool that allows to measure the shadow length of a boulder projected on the surrounding dust deposit, assuming that any height variation is not due to boulder intrinsic change. Any boulder height variation provides a direct measurement about the thickness variation of the surrounding dust layer due to the occurring erosion and/or accretion. The analysis concerns the period from 2014 August, inbound to perihelion, to 2016 September, outbound. We measured the erosion in the Ma’at region of 0.6 ± 0.2 m from 2014 September 12 to December 2, and an erosion of 0.4 ± 0.3 m from 2014 December 3 to 2015 February 15. Then, we measured a dust deposition of 0.7 ± 0.3 m during the following perihelion phase, until 2016 May–September. This result confirms the link between the erosion of the Southern hemisphere and the fallout in the northern regions. The Imhotep and Hatmehit regions are characterized by a negligible erosion during the inbound orbit, consistent with pebble-made nucleus models predicting no erosion when the temperature of the nucleus surface is Ts < 205 K.
Published: 2021

4. P 33 Changes in functional connectivity relate to modulation of cognitive control by subthalamic stimulation

Author: J. Achtzehn, F. Irmen, A. Horn, C. Güttler, A.L. de Almeida Marcelino, G. Wenzel, G.H. Schneider, W.J. Neumann, and A.A. Kühn
Subjects: Neurology, Physiology (medical), Neurology (clinical), Sensory Systems
Published: 2022
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5. Synthesis of the morphological description of cometary dust at comet 67P/Churyumov-Gerasimenko

Author: Martin Hilchenbach, Klaus Hornung, Alberto Flandes, Jérémie Lasue, Anny Chantal Levasseur-Regourd, Giovanna Rinaldi, Stavro Ivanovski, Marco Fulle, Harald Krüger, Andrea Longobardo, Dominique Bockelée-Morvan, Dennis Bodewits, Stefano Mottola, Yves Langevin, C. Güttler, Gianrico Filacchione, Ivano Bertini, G. P. Tozzi, Holger Sierks, Jürgen Blum, J. Agarwal, Fabrizio Capaccioni, Giampiero Naletto, Thurid Mannel, F. Moreno, Alessandra Rotundi, Imre Tóth, Sihane Merouane, V. Della Corte, John Paquette, Cecilia Tubiana, Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Max-Planck-Institut für Sonnensystemforschung (MPS), Space Research Institute of Austrian Academy of Sciences (IWF), Austrian Academy of Sciences (OeAW), Institute of Physics [Graz], Karl-Franzens-Universität [Graz, Autriche], Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), Istituto Nazionale di Astrofisica (INAF), Dipartimento di Scienze e Tecnologie [Napoli] (DIST), Universita degli studi di Napoli 'Parthenope' [Napoli], INAF - Osservatorio Astronomico di Trieste (OAT), Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), 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)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de recherche en astrophysique et planétologie (IRAP), 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), PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), 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), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Universita degli Studi di Padova, Dipartimento di Fisica e Astronomia 'Galileo Galilei', CNR Istituto di Fotonica e Nanotecnologie [Milano] (IFN), Consiglio Nazionale delle Ricerche [Roma] (CNR), Instituto de Geofisica [Mexico], Universidad Nacional Autónoma de México (UNAM), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Department of Physics [Auburn], Auburn University (AU), INAF - Osservatorio Astrofisico di Arcetri (OAA), Universität der Bundeswehr München [Neubiberg], Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Konkoly Observatory, Research Centre for Astronomy and Earth Sciences [Budapest], Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Karl-Franzens-Universität Graz, Università degli Studi di Napoli 'Parthenope' = University of Naples (PARTHENOPE), 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), 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), Università degli Studi di Padova = University of Padua (Unipd), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Universidad Nacional Autónoma de México = National Autonomous University of Mexico (UNAM), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), University of Graz, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), IMPEC - LATMOS, Technische Universität Braunschweig [Braunschweig], Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), ITA, FRA, DEU, and ESP
Subjects: Asteroiden und Kometen, instruments [space vehicles], 010504 meteorology & atmospheric sciences, comets: general – comets: individual: 67P/Churyumov-Gerasimenko – space vehicles: instruments, Computer science, Comet, Individual, 01 natural sciences, Space exploration, Astrobiology, Interplanetary dust cloud, individual: 67P/Churyumov-Gerasimenko [Comets], 0103 physical sciences, 67P/Churyumov-Gerasimenko - space vehicles, Comets, General - comets, Instruments, Instrumentation (computer programming), space vehicles: instruments, 010303 astronomy & astrophysics, ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, [PHYS]Physics [physics], Comets: individual: 67P/Churyumov-Gerasimenko, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], general [Comets], Astronomy and Astrophysics, Common framework, Comets: general, [SDU]Sciences of the Universe [physics], Space and Planetary Science
Abstract: Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. Open Access funding provided by Max Planck Society., Before Rosetta, the space missions Giotto and Stardust shaped our view on cometary dust, supported by plentiful data from Earth based observations and interplanetary dust particles collected in the Earth's atmosphere. The Rosetta mission at comet 67P/Churyumov-Gerasimenko was equipped with a multitude of instruments designed to study cometary dust. While an abundant amount of data was presented in several individual papers, many focused on a dedicated measurement or topic. Different instruments, methods, and data sources provide different measurement parameters and potentially introduce different biases. This can be an advantage if the complementary aspect of such a complex data set can be exploited. However, it also poses a challenge in the comparison of results in the first place. The aim of this work therefore is to summarize dust results from Rosetta and before. We establish a simple classification as a common framework for intercomparison. This classification is based on the dust particle structure, porosity, and strength and also on its size. Depending on the instrumentation, these are not direct measurement parameters, but we chose them because they were the most reliable for deriving our model. The proposed classification has proved helpful in the Rosetta dust community, and we offer it here also for a broader context. In this manner, we hope to better identify synergies between different instruments and methods in the future.© C. Güttler et al. 2019
Published: 2019
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6. Gas outflow and dust transport of comet 67P/Churyumov–Gerasimenko

Author: Francesco Marzari, Wing-Huen Ip, Laurent Jorda, J. Rainer Kramm, Hans Rickman, Gábor L. Kovács, Marc Hofmann, I. L. Lai, Philippe Lamy, Detlef Koschny, Jong-Shinn Wu, Mariolino De Cecco, Nilda Oklay, Ivano Bertini, Michael Küppers, Xian Shi, Nicolas Thomas, Stubbe F. Hviid, Jean-Loup Bertaux, Holger Sierks, C. Güttler, Olivier Groussin, Vania Da Deppo, Marco Fulle, Steven Boudreault, Pedro J. Gutiérrez, Giampiero Naletto, M. A. Barucci, Horst Uwe Keller, Michael F. A'Hearn, Jose J. Lopez Moreno, Jui Chi Lee, Ying Liao, Cesare Barbieri, Luisa Lara, Monica Lazzarin, Cheng Chin Su, Jean-Baptiste Vincent, Jakob Deller, Gabriele Cremonese, Ekkehard Kührt, Zhong-Yi Lin, Björn Davidsson, Cecilia Tubiana, Stefano Debei, Jessica Agarwal, Sonia Fornasier, Jörg Knollenberg, Rafael Rodrigo, Institute of Space Science [Taiwan], National Central University [Taiwan] (NCU), Institute of Astronomy [Taiwan] (IANCU), Space Science Institute [Macau] (SSI), Macau University of Science and Technology (MUST), Department of Mechanical Engineering [NCTU], National Chiao Tung University (NCTU), Department of Atmospheric Sciences [Taoyuan City], Physikalisches Institut [Bern], Universität Bern [Bern], Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Dipartimento di Fisica e Astronomia 'Galileo Galilei', Universita degli Studi di Padova, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Department of Physics and Astronomy [Uppsala], Uppsala University, Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, 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), 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), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), CNR Institute for Photonics and Nanotechnologies (IFN), Consiglio Nazionale delle Ricerche [Roma] (CNR), Department of Industrial Engineering [Padova], University of Trento [Trento], INAF - Osservatorio Astronomico di Trieste (OAT), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), European Space Astronomy Centre (ESAC), Department of Information Engineering [Padova] (DEI), Universität Bern [Bern] (UNIBE), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Università degli Studi di Padova = University of Padua (Unipd), Agence Spatiale Européenne = European Space Agency (ESA), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), ITA, USA, GBR, FRA, and DEU
Subjects: individual: comet 67P/Churyumov-Gerasimenko [comets], 010504 meteorology & atmospheric sciences, Astrophysics::High Energy Astrophysical Phenomena, Comet dust, Irregular shape, Comet, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, general [comets], methods: numerical, Astronomi, astrofysik och kosmologi, 0103 physical sciences, Comets: general, Comets: individual: comet 67P/Churyumov-Gerasimenko, Methods: numerical, Astronomy and Astrophysics, Space and Planetary Science, Astronomy, Astrophysics and Cosmology, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, Jet (fluid), [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Comet tail, 520 Astronomy, comets: general, Thermal cycle, Astronomy, numerical [methods], comets: individual: comet 67P/Churyumov-Gerasimenko, 620 Engineering, 13. Climate action, Outflow, Astrophysics::Earth and Planetary Astrophysics
Abstract: International audience; Because of the diurnal thermal cycle and the irregular shape of the nucleus, gas outflow of comet 67P/Churyumov–Gerasimenko could be highly anisotropic as indicated by the colliminated dust jet structures on the sunlit side. Based on the OSIRIS imaging observations of the outgassing effect, a simple model of surface sublimation can be constructed by taking into account the dependence on the solar insolation. With preliminary information on the time variability of the global gas production rate, a sequence of gas coma models can be generated at different epochs before and after perihelion. We also investigate different patterns of dust particle dynamics under the influences of nuclear rotation and gas drag. From these considerations, a consistent picture of the spatial distribution of dusty materials across the surface of comet 67P as it moves around the perihelion can be developed. It is found that because of the redeposition of the ejected dust from the Southern hemisphere to the Northern hemisphere during the southern summer season the Hapi region could gain up to 0.4 m while the Wosret region would lose up to 1.8 m of dust mantle per orbit.
Published: 2016
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7. Comet 67P/Churyumov-Gerasimenko through the eyes of the Rosetta/OSIRIS cameras

Author: C. Güttler
Subjects: Physics, biology, Comet, Astronomy, Osiris, biology.organism_classification
Published: 2018
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8. Multivariate statistical analysis of OSIRIS/Rosetta spectrophotometric data of comet 67P/Churyumov-Gerasimenko

Author: J. Knollenberg, H. U. Keller, Francesco Marzari, M. De Cecco, M. Hofmann, Sonia Fornasier, Detlef Koschny, Olivier Groussin, Nicolas Thomas, Jean-Loup Bertaux, J. J. Lopez Moreno, D. Perna, M. Küppers, J. D. P. Deshapriya, Cesare Barbieri, Stefano Debei, Marcello Fulchignoni, Jakob Deller, Rafael Rodrigo, Philippe Lamy, Holger Sierks, Wing-Huen Ip, Giampiero Naletto, Laurent Jorda, C. Güttler, M. A. Barucci, Ivano Bertini, Gabriele Cremonese, Marco Fulle, Michael F. A'Hearn, Pedro Hasselmann, L. M. Lara, Monica Lazzarin, Clement Feller, Jean-Baptiste Vincent, E. Kührt, Björn Davidsson, Stubbe F. Hviid, Cecilia Tubiana, R. Kramm, Nilda Oklay, V. Da Deppo, Mohamed Ramy El-Maarry, Hans Rickman, Pedro J. Gutiérrez, National Aeronautics and Space Administration (US), Ministry of Science and Technology (Taiwan), ITA, 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), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Dipartimento di Fisica e Astronomia 'Galileo Galilei', Universita degli Studi di Padova, Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Centro de Astrobiologia [Madrid] (CAB), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), International Space Science Institute [Bern] (ISSI), Research and Scientific Support Department, ESTEC (RSSD), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA)-European Space Agency (ESA), Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk = Polish Academy of Sciences (PAN), Department of Physics and Astronomy [Uppsala], Uppsala University, Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, 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), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), CNR Institute for Photonics and Nanotechnologies (IFN), Consiglio Nazionale delle Ricerche [Roma] (CNR), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Department of Industrial Engineering [Padova], University of Trento [Trento], Physikalisches Institut [Bern], Universität Bern [Bern], INAF - Osservatorio Astronomico di Trieste (OAT), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Institute of Astronomy [Taiwan] (IANCU), National Central University [Taiwan] (NCU), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], DLR Institute of Planetary Research, German Aerospace Center (DLR), European Space Astronomy Centre (ESAC), European Space Agency (ESA), Department of Information Engineering [Padova] (DEI), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Università degli Studi di Padova = University of Padua (Unipd), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Universität Bern [Bern] (UNIBE), Agence Spatiale Européenne = European Space Agency (ESA), and California Institute of Technology (CALTECH)-NASA
Subjects: Asteroiden und Kometen, 010504 meteorology & atmospheric sciences, Comet, Flux, Astrophysics, 01 natural sciences, 7. Clean energy, individual: 67P/Churyumov-Gerasimenko [Comets], Methods: data analysis, Comets: individual: 67P/Churyumov-Gerasimenko, Techniques: photometric, Rosetta, 0103 physical sciences, medicine, OSIRIS, data analysis [Methods], 010303 astronomy & astrophysics, Southern Hemisphere, 0105 earth and related environmental sciences, Physics, biology, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], photometric [Techniques], Northern Hemisphere, Astronomy, Astronomy and Astrophysics, biology.organism_classification, medicine.anatomical_structure, 13. Climate action, Space and Planetary Science, Homogeneous, Multivariate statistical, Osiris, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Nucleus
Abstract: Full list of authors: Perna, D.; Fulchignoni, M.; Barucci, M. A.; Fornasier, S.; Feller, C.; Deshapriya, J. D. P.; Hasselmann, P. H.; Sierks, H.; Barbieri, C.; Lamy, P. L.; Rodrigo, R.; Koschny, D.; Rickman, H.; A'Hearn, M.; Bertaux, J. -L.; Bertini, I.; Cremonese, G.; Da Deppo, V.; Davidsson, B.; Debei, S. Deller, J.; De Cecco, M.; El-Maarry, M. R.; Fulle, M.; Groussin, O.; Gutierrez, P. J.; Güttler, C.; Hofmann, M.; Hviid, S. F.; Ip, W. -H.; Jorda, L.; Keller, H. U.; Knollenberg, J.; Kramm, R.; Kührt, E.; Küppers, M.; Lara, L. M.; Lazzarin, M.; Lopez Moreno, J. J.; Marzari, F.; Naletto, G.; Oklay, N.; Thomas, N.; Tubiana, C.; Vincent, J. -B., Context. The ESA Rosetta mission explored comet 67P/Churyumov-Gerasimenko in 2014-2016, following its target before and after the perihelion passage on 13 August 2015. The NAC camera of the OSIRIS imaging system allowed to map the nucleus surface acquiring images with different filters in the visible wavelength range. Aims. Here we study the spectrophotometric behaviour of the nucleus by a multivariate statistical analysis, aiming to distinguish homogeneous groups and to constrain the bulk composition. Methods. We applied the G-mode clustering algorithm to 16 OSIRIS data cubes acquired on 5-6 August 2014 (mostly covering the northern hemisphere) and 2 May 2015 (mostly covering the southern hemisphere), selected to have complete coverage of the comet's surface with similar observing conditions. Results. We found four similar homogeneous groups for each of the analysed cubes. The first group corresponds to the average spectrophotometric behaviour of the nucleus. The second (spectrally redder) and the third (spectrally bluer) groups are found in regions that were already found to deviate from the average terrain of the comet by previous studies. A fourth group (characterised by enhancements of the flux at 700-750 nm and 989 nm, possibly due to HO and/or NH emissions) seems connected with the cometary activity rather than with the bulk composition. Conclusions. While our aim in this work was to study the spectrophotometric behaviour of the nucleus of 67P/Churyumov-Gerasimenko as a whole, we found that a follow-up application of the G-mode to smaller regions of the surface could be useful in particular to identify and study the temporal evolution of ice patches, as well as to constrain the composition and physical processes behind the emission of dust jets. © ESO, 2017., OSIRIS was built by a consortium of the Max-Planck-Institut fur Sonnensystemforschung, Gottingen, Germany, CISAS-University of Padova, Italy, the Laboratoire d'Astrophysique de Marseille, France, the Instituto de Astrofisica de Andalucia, CSIC, Granada, Spain, the Research and Scientific Support Department of the European Space Agency, Noordwijk, The Netherlands, the Instituto Nacional de Tecnica Aeroespacial, Madrid, Spain, the Universidad Politechnica de Madrid, Spain, the Department of Physics and Astronomy of Uppsala University, Sweden, and the Institut fur Datentech-nik und Kommunikationsnetze der Technischen Universitat Braunschweig, Germany. The support of the national funding agencies of Germany (DLR), France (CNES), Italy (ASI), Spain (MEC), Sweden (SNSB), and the ESA Technical Directorate is gratefully acknowledged. M.A. acknowledges NASA funding through Jet Propulsion Laboratory contract No. 1267923 and from the Akademie der Wissenschaften zu Gottingen. W.-H.Ip acknowledges the Ministry of Science and Technology, Taiwan (grant No. NSC 102-2112-M-008) and Macau University of Science and Technology (grant No. FDCT 017/2014/A1). We thank the ESA teams at European Space Astronomy Centre, European Space Operations Centre, and European Space Research and Technology Centre for their work in support of the Rosetta mission. Rosetta/OSIRIS data are available through the ESA's Planetary Science Archive (PSA, http://www.cosmos.esa.int/web/psa/rosetta).
Published: 2017
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9. Seasonal erosion and restoration of the dust cover on comet 67P/Churyumov‐Gerasimenko as observed by OSIRIS onboard Rosetta

Author: Cesare Barbieri, Maria Antonieta Barucci, Jakob Deller, Gabriele Cremonese, Marco Fulle, Olivier Groussin, Jean-Loup Bertaux, J. Knollenberg, M. Küppers, Stefano Debei, Monica Lazzarin, L. M. Lara, Pedro J. Gutiérrez, Jean-Baptiste Vincent, C. Güttler, H. U. Keller, Maurizio Pajola, Géza Kovács, Ivano Bertini, Mohamed Ramy El-Maarry, Detlef Koschny, Hans Rickman, Nicolas Thomas, Holger Sierks, Sonia Fornasier, E. Kührt, A. Gicquel, J.-R. Kramm, Xian Shi, Dennis Bodewits, Nilda Oklay, X. Hu, V. Da Deppo, Björn Davidsson, Stefano Mottola, Cecilia Tubiana, Giampiero Naletto, P. Gutierrez-Marques, Rafael Rodrigo, Matteo Massironi, Stubbe F. Hviid, Jürgen Blum, Philippe Lamy, Wing-Huen Ip, Jessica Agarwal, Laurent Jorda, M. Hofmann, M. De Cecco, Bastian Gundlach, Steve Boudreault, J. J. López-Moreno, S. Höfner, Michael F. A'Hearn, Francesco Marzari, Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], INAF - Osservatorio Astronomico di Trieste (OAT), Istituto Nazionale di Astrofisica (INAF), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), NASA Ames Research Center (ARC), Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, INAF - Osservatorio Astronomico di Padova (OAPD), 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), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Dipartimento di Fisica e Astronomia 'Galileo Galilei', Università degli Studi di Padova = University of Padua (Unipd), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), International Space Science Institute [Bern] (ISSI), Research and Scientific Support Department, ESTEC (RSSD), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), Department of Physics and Astronomy [Uppsala], Uppsala University, Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk = Polish Academy of Sciences (PAN), 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), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), CNR Istituto di Fotonica e Nanotecnologie [Padova] (IFN), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Department of Industrial Engineering [Padova], Università degli Studi di Trento (UNITN), Physikalisches Institut [Bern], Universität Bern [Bern] (UNIBE), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Institute of Astronomy [Taiwan] (IANCU), National Central University [Taiwan] (NCU), Operations Department (ESAC), European Space Astronomy Centre (ESAC), Department of Information Engineering [Padova] (DEI), Center for Space and Habitability (CSH), University of Bern, Max-Planck-Institut für Sonnensystemforschung (MPS), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Universita degli Studi di Padova, Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), European Space Agency (ESA)-European Space Agency (ESA), Consiglio Nazionale delle Ricerche [Roma] (CNR), Universität Bern [Bern], European Space Agency, Centre National de la Recherche Scientifique (France), Agenzia Spaziale Italiana, Swedish National Space Board, Ministerio de Economía y Competitividad (España), International Max Planck Research Schools, German Centre for Air and Space Travel, and California Institute of Technology (CALTECH)-NASA
Subjects: Comets: general, Comets: individual: 67P/Churyumov-Gerasimenko, Astronomy and Astrophysics, Space and Planetary Science, 67P/Churyumov-Gerasimenko, 010504 meteorology & atmospheric sciences, Comet dust, Comet, Context (language use), Atmospheric sciences, 01 natural sciences, Latitude, Astrobiology, thermal modeling, individual: 67P/Churyumov [Comets], Rosetta, 0103 physical sciences, medicine, comets, Ejecta, 010303 astronomy & astrophysics, Comets: individual: 67P/Churyumov, Gerasimenko, 0105 earth and related environmental sciences, Physics, Polar night, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], general [Comets], Seasonality, erosion, medicine.disease, 13. Climate action, [SDU]Sciences of the Universe [physics], Erosion, sense organs
Abstract: Context. Dust deposits or dust cover are a prevalent morphology in the northern hemi-nucleus of comet 67P/Churyumov-Gerasimenko (67P). The evolution of the dust deposits was captured by the OSIRIS camera system onboard the Rosetta spacecraft having escorted the comet for over two years. The observations shed light on the fundamental role of cometary activity in shaping and transforming the surface morphology. Aims. We aim to present OSIRIS observations of surface changes over the dust deposits before and after perihelion. The distribution of changes and a timeline of their occurrence are provided. We perform a data analysis to quantify the surface changes and investigate their correlation to water activity from the dust deposits. We further discuss how the results of our investigation are related to other findings from the Rosetta mission. Methods. Surface changes were detected via systematic comparison of images, and quantified using shape-from-shading technique. Thermal models were applied to estimate the erosion of water ice in response to the increasing insolation over the areas where surface changes occurred. Modeling results were used for the interpretation of the observed surface changes. Results. Surface changes discussed here were concentrated at mid-latitudes, between about 20â-N and 40â-N, marking a global transition from the dust-covered to rugged terrains. The changes were distributed in open areas exposed to ample solar illumination and likely subject to enhanced surface erosion before perihelion. The occurrence of changes followed the southward migration of the sub-solar point across the latitudes of their distribution. The erosion at locations of most changes was at least about 0.5 m, but most likely did not exceed several meters. The erosive features before perihelion had given way to a fresh, smooth cover of dust deposits after perihelion, suggesting that the dust deposits had been globally restored by at least about 1 m with ejecta from the intensely illuminated southern hemi-nucleus around perihelion, when the north was inactive during polar night. Conclusions. The erosion and restoration of the northern dust deposits are morphological expressions of seasonality on 67P. Based on observations and thermal modeling results, it is inferred that the dust deposits contained a few percent of water ice in mass on average. Local inhomogeneity in water abundance at spatial scales below tens of meters is likely. We suspect that dust ejected from the deposits may not have escaped the comet in bulk. That is, at least half of the ejected mass was afloat in the inner-coma or/and redeposited over other areas of the nucleus.© 2017 ESO., X. Hu acknowledges the financial support from the International Max Planck Research School for Solar System Science in Gottingen.The support of the national funding agencies of Germany (DLR), France (CNES), Italy (ASI), Spain (MEC), Sweden (SNSB), and the ESA Technical Directorate is gratefully acknowledged.
Published: 2017
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10. Thermal modelling of water activity on comet 67P/Churyumov-Gerasimenko with global dust mantle and plural dust-to-ice ratio

Author: J.-R. Kramm, J.-B. Vincent, Michael Küppers, X. Hu, Gabriele Cremonese, J. J. López-Moreno, J. Agarwal, Marco Fulle, I. Hall, Maria Antonieta Barucci, M. F. A'Hearn, Björn Davidsson, Stefano Debei, Olivier Groussin, Ivano Bertini, J. Ripken, Maurizio Pajola, Ekkehard Kührt, Stubbe F. Hviid, Cecilia Tubiana, L. M. Lara, J. L. Bertaux, Giampiero Naletto, I. Büttner, Cesare Barbieri, Sonia Fornasier, Xian Shi, Nilda Oklay, R. Rodrigo, Juergen Oberst, Jakob Deller, Stefano Mottola, P. Gutierrez-Marques, C. Güttler, Detlef Koschny, Francesco Marzari, V. Da Deppo, Nicolas Thomas, P. J. Gutierrez, Jürgen Blum, Monica Lazzarin, Hans Rickman, Géza Kovács, H. U. Keller, Holger Sierks, Jörg Knollenberg, M. L. Richards, Wing-Huen Ip, Philippe Lamy, Laurent Jorda, Marc Hofmann, Steve Boudreault, M. De Cecco, Bastian Gundlach, Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Technische Universität Berlin (TU), Institut für Geodäsie und Geoinformationstechnik, Moscow State University of Geodesy and Cartography (MIIGAiK), INAF - Osservatorio Astronomico di Trieste (OAT), Istituto Nazionale di Astrofisica (INAF), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), NASA Ames Research Center (ARC), Dipartimento di Fisica e Astronomia 'Galileo Galilei', Universita degli Studi di Padova, Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), International Space Science Institute [Bern] (ISSI), Centro de Astrobiologia [Madrid] (CAB), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk = Polish Academy of Sciences (PAN), Department of Physics and Astronomy [Uppsala], Uppsala University, Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, 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), 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), INAF - Osservatorio Astronomico di Padova (OAPD), CNR Institute for Photonics and Nanotechnologies (IFN), Consiglio Nazionale delle Ricerche [Roma] (CNR), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Department of Industrial Engineering [Padova], University of Trento [Trento], Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), DLR Institute of Planetary Research, German Aerospace Center (DLR), Institute of Space Science [Taiwan], National Central University [Taiwan] (NCU), Operations Department (ESAC), European Space Astronomy Centre (ESAC), European Space Agency (ESA)-European Space Agency (ESA), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Department of Information Engineering [Padova] (DEI), Physikalisches Institut [Bern], Universität Bern [Bern], Center for Space and Habitability (CSH), University of Bern, Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Technical University of Berlin / Technische Universität Berlin (TU), Università degli Studi di Padova = University of Padua (Unipd), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Agence Spatiale Européenne = European Space Agency (ESA), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), Universität Bern [Bern] (UNIBE), and California Institute of Technology (CALTECH)-NASA
Subjects: Solid state: refractory, Asteroiden und Kometen, 67P/Churyumov-Gerasimenko, Insolation, 010504 meteorology & atmospheric sciences, Water activity, Comet, Volatile, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], 01 natural sciences, Mantle (geology), Solid state: volatile -methods: numerical, Astrobiology, 0103 physical sciences, Thermal, Comets, medicine, Comets: individual (67P/Churyumov-Gerasimenko), 010303 astronomy & astrophysics, Comets: general, 0105 earth and related environmental sciences, [PHYS]Physics [physics], Physics, Refractory, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], 520 Astronomy, Planetengeodäsie, Astronomy and Astrophysics, Geophysics, 620 Engineering, medicine.anatomical_structure, Space and Planetary Science, Sublimation (phase transition), Numerical methods, Water ice, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Nucleus
Abstract: International audience; We perform a thermo-physical analysis on water activity of comet 67P/Churyumov-Gerasimenko (67P). The sublimation of water is assumed to occur from beneath a global, desiccated dust mantle over the irregular-shaped nucleus. The concept of two thermal models, the recipe of model formulation and the strategy of application to comet 67P are described. For an accurate and efficient evaluation of energy input by insolation and self-heating over the nucleus, a Landscape data base is devised based on polyhedral shape models of the nucleus. We apply the thermal models to investigate the impact of certain parameters of nucleus properties on water production. It is found that the measured water production of 67P can be overall attributed to sublimation of water ice with a mass abundance of a few to 10 per cent beneath a uniform dust mantle of several millimetres to one centimetre in thickness. Insofar as 67P is concerned, we argue against the necessity to invoke assumptions on localized water activity, or on the distinction of active/dormant surface areas.
Published: 2017
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11. Surface evolution of the Anhur region on comet 67P/Churyumov-Gerasimenko from high-resolution OSIRIS images

Author: R. Rodrigo, M. De Cecco, Stefano Debei, P. J. Gutierrez, Ivano Bertini, J. M. Sunshine, P. L. Lamy, Detlef Koschny, S. Fornasier, Xian Shi, Laurent Jorda, G. Cremonese, J. B. Vincent, Marco Fulle, Imre Tóth, Maurizio Pajola, M. L. Lara, J. L. Bertaux, Sabrina Ferrari, C. Güttler, V. Da Deppo, Dennis Bodewits, M. A. Barucci, W-H. Ip, Jakob Deller, Holger Sierks, Clement Feller, Stefano Mottola, Monica Lazzarin, Alice Lucchetti, Cecilia Tubiana, J. J. Lopez Moreno, B. J. R. Davidsson, Horst Uwe Keller, Giampiero Naletto, Francesco Marzari, Pedro Hasselmann, Laboratoire d'études spatiales et d'instrumentation en astrophysique (LESIA (UMR_8109)), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Universita degli Studi di Padova, Dipartimento di Fisica e Astronomia 'Galileo Galilei', CNR Istituto di Fotonica e Nanotecnologie [Padova] (IFN), Consiglio Nazionale delle Ricerche [Roma] (CNR), IMPEC - 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), Centro de Astrobiologia [Madrid] (CAB), Consejo Superior de Investigaciones Científicas [Spain] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), International Space Science Institute [Bern] (ISSI), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Space Research Institute of the Russian Academy of Sciences (IKI), Russian Academy of Sciences [Moscow] (RAS), Department of Physics [Auburn], Auburn University (AU), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), CNR Institute for Photonics and Nanotechnologies (IFN), Department of Mechanical Engineering [Padova], Department of Industrial Engineering [Padova], Universita degli Studi di Padova-Universita degli Studi di Padova, University of Trento [Trento], Dipartimento di Geoscienze [Padova], INAF - Osservatorio Astronomico di Trieste (OAT), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Institute of Astronomy [Taiwan] (IANCU), National Central University [Taiwan] (NCU), Space Science Institute [Macau] (SSI), Macau University of Science and Technology (MUST), Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig [Braunschweig], European Space Astronomy Centre (ESAC), Konkoly Observatory, Research Centre for Astronomy and Earth Sciences [Budapest], Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université Paris Diderot - Paris 7 (UPD7)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), PLANETO - LATMOS, 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), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), California Institute of Technology (CALTECH)-NASA, Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], German Centre for Air and Space Travel, Centre National D'Etudes Spatiales (France), Agenzia Spaziale Italiana, Agencia Estatal de Investigación (España), European Space Agency, Swedish National Space Agency, Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Università degli Studi di Padova = University of Padua (Unipd), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Agence Spatiale Européenne = European Space Agency (ESA), Università degli Studi di Padova = University of Padua (Unipd)-Università degli Studi di Padova = University of Padua (Unipd), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), ANR-17-CE31-0004,CLASSY,Composition des surfaces du Système Solaire de bas albédo(2017), ITA, USA, GBR, FRA, and DEU
Subjects: 67P/Churyumov-Gerasimenko, Asteroiden und Kometen, photometry, 010504 meteorology & atmospheric sciences, Comet, observational [methods], Data analysis, Narrow angle, High resolution, Individual, rosetta mission, Equinox, Photometric, imaging spectroscopy, Fault scarp, 01 natural sciences, photometric [techniques], techniques: photometric, individual: 67P/Churyumov-Gerasimenko [Comets], 0103 physical sciences, data analysis [methods], Methods, comets, Observational, 010303 astronomy & astrophysics, Southern Hemisphere, 0105 earth and related environmental sciences, [PHYS]Physics [physics], [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], biology, comets: individual: 67P/Churyumov-Gerasimenko, Astronomy, Astronomy and Astrophysics, imaging spectroscopy [techniques], biology.organism_classification, methods: data analysis, Techniques, techniques: imaging spectroscopy, 13. Climate action, Space and Planetary Science, Radiance, Comets, Imaging spectroscopy, methods: observational, Osiris, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Geology
Abstract: Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited., The southern hemisphere of comet 67P/Churyumov-Gerasimenko (67P) became observable by the Rosetta mission in March 2015, a few months before cometary southern vernal equinox. The Anhur region in the southern part of the comet's larger lobe was found to be highly eroded, enriched in volatiles, and highly active. Aims. We analyze high-resolution images of the Anhur region pre- and post-perihelion acquired by the OSIRIS imaging system on board the Rosetta mission. The Narrow Angle Camera is particularly useful for studying the evolution in Anhur in terms of morphological changes and color variations. Methods. Radiance factor images processed by the OSIRIS pipeline were coregistered, reprojected onto the 3D shape model of the comet, and corrected for the illumination conditions. Results. We find a number of morphological changes in the Anhur region that are related to formation of new scarps; removal of dust coatings; localized resurfacing in some areas, including boulders displacements; and vanishing structures, which implies localized mass loss that we estimate to be higher than 50 million kg. The strongest changes took place in and nearby the Anhur canyon-like structure, where significant dust cover was removed, an entire structure vanished, and many boulders were rearranged. All such changes are potentially associated with one of the most intense outbursts registered by Rosetta during its observations, which occurred one day before perihelion passage. Moreover, in the niche at the foot of a new observed scarp, we also see evidence of water ice exposure that persisted for at least six months. The abundance of water ice, evaluated from a linear mixing model, is relatively high (>20%). Our results confirm that the Anhur region is volatile-rich and probably is the area on 67P with the most pristine exposures near perihelion.© S. Fornasier et al. 2019, OSIRIS was built by a consortium led by the Max-Planck-Institut fur Sonnensystemforschung, Goettingen, Germany, in collaboration with CISAS, University of Padova, Italy, the Laboratoire d'Astrophysique de Marseille, France, the Instituto de Astrofisica de Andalucia, CSIC, Granada, Spain, the Scientific Support Office of the European Space Agency, Noordwijk, The Netherlands, the Instituto Nacional de Tecnica Aeroespacial, Madrid, Spain, the Universidad Politechnica de Madrid, Spain, the Department of Physics and Astronomy of Uppsala University, Sweden, and the Institut fur Datentechnik und Kommunikationsnetze der Technischen Universitat Braunschweig, Germany. The support of the national funding agencies of Germany (DLR), France (CNES), Italy (ASI), Spain (MEC), Sweden (SNSB), and the ESA Technical Directorate is gratefully acknowledged. We thank the Rosetta Science Ground Segment at ESAC, the Rosetta Mission Operations Centre at ESOC and the Rosetta Project at ESTEC for their outstanding work enabling the science return of the Rosetta Mission. SF acknowledges the financial support from the France Agence Nationale de la Recherche (programme Classy, ANR-17-CE31-0004). The authors thank Dr. E. Howell for her comments and suggestions which helped us to improve this article.
Published: 2019
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12. Rosetta’s comet 67P/Churyumov-Gerasimenko sheds its dusty mantle to reveal its icy nature

Author: M. Küppers, Maurizio Pajola, M. L. Lara, Giampiero Naletto, Jean-Loup Bertaux, J. D. P. Deshapriya, J. J. Lopez Moreno, Imre Toth, Ivano Bertini, Nilda Oklay, M. A. Barucci, Frank Scholten, Gabriele Cremonese, M. De Cecco, V. Da Deppo, Marco Fulle, Sonia Fornasier, Wing-Huen Ip, Olivier Groussin, Laurent Jorda, E. Kührt, Holger Sierks, Géza Kovács, Cesare Barbieri, Sebastien Besse, Jakob Deller, J. Knollenberg, Antoine Pommerol, Björn Davidsson, Stefano Debei, Philippe Lamy, R. Kramm, Cecilia Tubiana, C. Güttler, H. U. Keller, Rafael Rodrigo, Monica Lazzarin, Xian Shi, Jean-Baptiste Vincent, Stefano Mottola, Jessica Agarwal, Pedro J. Gutiérrez, Clement Feller, M. Hofmann, Matteo Massironi, Detlef Koschny, Nicolas Thomas, Stubbe F. Hviid, Mohamed Ramy El-Maarry, Hans Rickman, Francesco Marzari, Frank Preusker, Michael F. A'Hearn, 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), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Jet Propulsion Laboratory (JPL), California Institute of Technology (CALTECH)-NASA, Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Dipartimento di Fisica e Astronomia 'Galileo Galilei', Universita degli Studi di Padova, Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), International Space Science Institute [Bern] (ISSI), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk = Polish Academy of Sciences (PAN), Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, 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), Operations Department (ESAC), European Space Astronomy Centre (ESAC), European Space Agency (ESA)-European Space Agency (ESA), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), CNR Institute for Photonics and Nanotechnologies (IFN), Consiglio Nazionale delle Ricerche [Roma] (CNR), Department of Industrial Engineering [Padova], University of Trento [Trento], Physikalisches Institut [Bern], Universität Bern [Bern], INAF - Osservatorio Astronomico di Trieste (OAT), Institute of Space Science [Taiwan], National Central University [Taiwan] (NCU), Space Science Institute [Macau] (SSI), Macau University of Science and Technology (MUST), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Department of Information Engineering [Padova] (DEI), CNR Istituto di Fotonica e Nanotecnologie [Padova] (IFN), NASA Ames Research Center (ARC), Konkoly Observatory, Research Centre for Astronomy and Earth Sciences [Budapest], Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), NASA-California Institute of Technology (CALTECH), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Università degli Studi di Padova = University of Padua (Unipd), Agence Spatiale Européenne = European Space Agency (ESA), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Universität Bern [Bern] (UNIBE), ITA, USA, GBR, FRA, and DEU
Subjects: 67P/Churyumov-Gerasimenko, 010504 meteorology & atmospheric sciences, osiris, H2O ICE, 01 natural sciences, EXPOSED WATER ICE, Mantle (geology), Nucleus, Astrobiology, rosetta, comet, 0103 physical sciences, morphology, medicine, surface, virtis, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Multidisciplinary, Medicine (all), medicine.anatomical_structure, data, 13. Climate action, [SDU]Sciences of the Universe [physics], Cyclic process, Sublimation (phase transition), Water ice, Surface dust, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Geology
Abstract: Rosetta observes sublimating surface ices Comets are “dirty snowballs” made of ice and dust, but they are dark because the ice sublimates away, leaving some of the dust behind on the surface. The Rosetta spacecraft has provided a close-up view of the comet 67P/Churyumov-Gerasimenko as it passes through its closest point to the Sun (see the Perspective by Dello Russo). Filacchione et al. detected the spectral signature of solid CO 2 (dry ice) in small patches on the surface of the nucleus as they emerged from local winter. By modeling how the CO 2 sublimates, they constrain the composition of comets and how ices generate the gaseous coma and tail. Fornasier et al. studied images of the comet and discovered bright patches on the surface where ice was exposed, which disappeared as the ice sublimated. They also saw frost emerging from receding shadows. The surface of the comet was noticeably less red just after local dawn, indicating that icy material is removed by sunlight during the local day. Science , this issue p. 1563 , p. 1566 ; see also p. 1536
Published: 2016
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13. Decimetre-scaled spectrophotometric properties of the nucleus of comet 67P/Churyumov-Gerasimenko from OSIRIS observations

Author: Clement Feller, Wing-Huen Ip, Laurent Jorda, Marco Fulle, M. Küppers, Pedro Hasselmann, Nilda Oklay, Philippe Lamy, Björn Davidsson, Antoine Pommerol, Holger Sierks, Cecilia Tubiana, Stefano Debei, V. Da Deppo, Antonella Barucci, Stubbe F. Hviid, Jean-Loup Bertaux, Pedro J. Gutiérrez, F. Scholten, Olivier Groussin, A. Giquel, Detlef Koschny, Cesare Barbieri, Nicolas Thomas, Jakob Deller, Sonia Fornasier, E. Kührt, M. De Cecco, Nafiseh Masoumzadeh, C. Leyrat, J. Knollenberg, Irina Belskaya, Monica Lazzarin, D. Perna, Gabriele Cremonese, Olivier Poch, H. U. Keller, M. R. Elmaary, Jean-Baptiste Vincent, Rafael Rodrigo, Hans Rickman, Steve Boudreault, Maurizio Pajola, J.-R. Kramm, Xian Shi, Stefano Mottola, Bernhard Jost, Francesco Marzari, Giampiero Naletto, F. Preusker, C. Güttler, J. J. Lopez Moreno, Jessica Agarwal, Géza Kovács, M. L. Lara, Ivano Bertini, Michael F. A'Hearn, M. Hofmann, 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), DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Physikalisches Institut [Bern], Universität Bern [Bern] (UNIBE), V.N. Karazin Kharkiv National University (KhNU), NASA Ames Research Center (ARC), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Università degli Studi di Padova = University of Padua (Unipd), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Dipartimento di Fisica e Astronomia 'Galileo Galilei', Research and Scientific Support Department, ESTEC (RSSD), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), Department of Physics and Astronomy [Uppsala], Uppsala University, Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk = Polish Academy of Sciences (PAN), International Space Science Institute [Bern] (ISSI), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, 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), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), CNR Institute for Photonics and Nanotechnologies (IFN), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Department of Industrial Engineering [Padova], University of Trento [Trento], INAF - Osservatorio Astronomico di Trieste (OAT), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Institute of Astronomy [Taiwan] (IANCU), National Central University [Taiwan] (NCU), Department of Information Engineering [Padova] (DEI), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Universität Bern [Bern], Universita degli Studi di Padova, Max-Planck-Institut für Sonnensystemforschung (MPS), European Space Agency (ESA)-European Space Agency (ESA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), Consiglio Nazionale delle Ricerche [Roma] (CNR), California Institute of Technology (CALTECH)-NASA, European Space Agency, Swedish National Space Board, Ministerio de Economía y Competitividad (España), German Centre for Air and Space Travel, Centre National de la Recherche Scientifique (France), and Agenzia Spaziale Italiana
Subjects: instruments [space vehicles], 010504 meteorology & atmospheric sciences, Infrared, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], 01 natural sciences, methods: data analysis – space vehicles – space vehicles: instruments – techniques: image processing – techniques: photometric – comets: individual: 67P/ Churyumov–Gerasimenko, methods: data analysis space vehicles space vehicles: instruments techniques: image processing techniques: photometric comets: individual: 67P/Churyumov Gerasimenko, photometric [techniques], Astronomi, astrofysik och kosmologi, Geometric albedo, Spectral slope, Astronomy, Astrophysics and Cosmology, Space vehicles: instruments, comets, 010303 astronomy & astrophysics, Image resolution, Physics, Earth and Planetary Astrophysics (astro-ph.EP), biology, image processing [techniques], 7P/Churyumov Gerasimenko, 520 Astronomy, Comets: individual: 67P/Churyumov-gerasimenko, Methods: data analysis, Space vehicles, Techniques: image processing, Techniques: photometric, medicine.anatomical_structure, individual: 67P/Churyumov-Gerasimenko [comets], photometry, 530 Physics, Comet, Data analysis, FOS: Physical sciences, Photometry (optics), 0103 physical sciences, medicine, data analysis [methods], 0105 earth and related environmental sciences, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Astronomy, Astronomy and Astrophysics, 620 Engineering, biology.organism_classification, image processing, 13. Climate action, Space and Planetary Science, space vehicles, Osiris, Nucleus, Astrophysics - Earth and Planetary Astrophysics
Abstract: We present the results of the photometric and spectrophotometric properties of the 67P/Churyumov¿Gerasimenko nucleus derived with the Optical, Spectroscopic and Infrared Remote Imaging System instrument during the closest fly-by over the comet, which took place on 2015 February 14 at a distance of ~6 km from the surface. Several images covering the 0¿¿ 33¿ phase angle range were acquired, and the spatial resolution achieved was 11 cm pixel¿1. The flown-by region is located on the big lobe of the comet, near the borders of the Ash, Apis and Imhotep regions. Our analysis shows that this region features local heterogeneities at the decimetre scale. We observed difference of reflectance up to 40 per cent between bright spots and sombre regions, and spectral slope variations up to 50 per cent. The spectral reddening effect observed globally on the comet surface by Fornasier et al. (2015) is also observed locally on this region, but with a less steep behaviour. We note that numerous metre-sized boulders, which exhibit a smaller opposition effect, also appear spectrally redder than their surroundings. In this region, we found no evidence linking observed bright spots to exposed water-ice-rich material.We fitted our data set using the Hapke 2008 photometric model. The region overflown is globally as dark as the whole nucleus (geometric albedo of 6.8 per cent) and it has a high porosity value in the uppermost layers (86 per cent). These results of the photometric analysis at a decimetre scale indicate that the photometric properties of the flown-by region are similar to those previously found for the whole nucleus. © 2016 The Authors., The support of the national funding agencies of Germany (DLR), France (CNES), Italy (ASI), Spain (MEC), Sweden (SNSB) and the ESA Technical Directorate is gratefully acknowledged.
Published: 2016
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14. Observations and analysis of a curved jet in the coma of comet 67P/Churyumov-Gerasimenko

Author: Jörg Knollenberg, Monica Lazzarin, M. F. A'Hearn, Michael Küppers, Jong-Shinn Wu, J.-C. Lee, Ivano Bertini, M. A. Barucci, Wing-Huen Ip, Laurent Jorda, L. M. Lara, P. L. Lamy, Horst Uwe Keller, G. Cremonese, Agata Rozek, Cesare Barbieri, Maurizio Pajola, Nicolas Thomas, J. J. Lopez-Moreno, C. C. Su, J.-R. Kramm, S. Debet, M. De Cecco, Cecilia Tubiana, Giampiero Naletto, F. La Forgia, S. Fornasier, Ekkehard Kührt, Stefano Mottola, I. L. Lai, Francesco Marzari, J. Agarwal, Detlef Koschny, Zhong-Yi Lin, Stubbe F. Hviid, C. Güttler, V. Da Deppo, Géza Kovács, Stephen C. Lowry, R. Rodrigo, Hans Rickman, Marco Fulle, P. J. Gutierrez, Olivier Groussin, Dennis Bodewits, Harald Michalik, J. L. Bertaux, B. J. R. Davidsson, Holger Sierks, N. Oklay, J. B. Vincent, Institute of Astronomy [Taiwan] (IANCU), National Central University [Taiwan] (NCU), Institute of Space Science [Taiwan], Department of Mechanical Engineering [NCTU], National Chiao Tung University (NCTU), Space Science Institute [Macau] (SSI), Macau University of Science and Technology (MUST), Department of Atmospheric Sciences [Taoyuan City], Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Dipartimento di Fisica e Astronomia 'Galileo Galilei', Università degli Studi di Padova = University of Padua (Unipd), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), International Space Science Institute [Bern] (ISSI), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Research and Scientific Support Department, ESTEC (RSSD), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk = Polish Academy of Sciences (PAN), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, 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), 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), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), CNR Institute for Photonics and Nanotechnologies (IFN), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Department of Physics and Astronomy [Uppsala], Uppsala University, Department of Industrial Engineering [Padova], University of Trento [Trento], INAF - Osservatorio Astronomico di Trieste (OAT), Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), DLR Institute of Planetary Research, German Aerospace Center (DLR), European Space Astronomy Centre (ESAC), Agence Spatiale Européenne = European Space Agency (ESA), Centre for Astrophysics and Planetary Science [Canterbury] (CAPS), University of Kent [Canterbury], Department of Information Engineering, Physikalisches Institut [Bern], Universität Bern [Bern] (UNIBE), National funding agencies of Germany (DLR), France (CNES), Italy (Agenzia Spaziale Italiana), Spain (Ministerio de Educación, Cultura y Deporte), Sweden (Swedish National Space Board), ESA, Ministry of Science and Technology of Taiwan, Max-Planck-Institut für Sonnensystemforschung (MPS), Universita degli Studi di Padova, European Space Agency (ESA)-European Space Agency (ESA), Consiglio Nazionale delle Ricerche [Roma] (CNR), European Space Agency (ESA), Universität Bern [Bern], Ministerio de Educación, Cultura y Deporte (España), Swedish National Space Board, European Space Agency, Agenzia Spaziale Italiana, Centre National D'Etudes Spatiales (France), German Centre for Air and Space Travel, National Science and Technology Development Agency (Thailand), ITA, USA, GBR, FRA, and DEU
Subjects: 67P/Churyumov-Gerasimenko, Gravity (chemistry), 010504 meteorology & atmospheric sciences, Terminal velocity, 530 Physics, Comet, Equator, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, Coma (optics), Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, individual: 67P/Churyumov-Gerasimenko [Comets], 0103 physical sciences, medicine, comets, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Comets: individual: 67P/Churyumov-Gerasimenko, Jet (fluid), Astronomy and Astrophysics, Space and Planetary Science, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], 520 Astronomy, 620 Engineering, medicine.anatomical_structure, Drag, Astrophysics::Earth and Planetary Astrophysics, Nucleus, Astrophysics - Earth and Planetary Astrophysics
Abstract: Aims. We analyze the physical properties and dynamical origin of a curved jet of comet 67P/Churyumov-Gerasimenko that was observed repeatedly in several nucleus rotations starting on May 30 and persisting until early August, 2015. Methods. We simulated the motion of dust grains ejected from the nucleus surface under the influence of the gravity and viscous drag effect of the expanding gas flow from the rotating nucleus. Results. The formation of the curved jet is a combination of the size of the dust particles (∼0.1-1 mm) and the location of the source region near the nucleus equator. This enhances the spiral feature of the collimated dust stream after the dust is accelerated to a terminal speed on the order of m s. © ESO, 2016., The support of the national funding agencies of Germany (Deutschen Zentrums fur Luft- und Raumfahrt), France (Centre National d'Etudes Spatiales), Italy (Agenzia Spaziale Italiana), Spain (Ministerio de Educacion, Cultura y Deporte), Sweden (Swedish National Space Board; grant no. 74/10:2), and the ESA Technical Directorate is gratefully acknowledged. This work was also supported by grant number NSC 102-2112-M-008-013-MY3 and MOST 104-2119-M-008-024 from the Ministry of Science and Technology of Taiwan. We are indebted to the whole Rosetta mission team, Science Ground Segment, and Rosetta Mission Operation Control for their hard work making this mission possible.
Published: 2016
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15. Are fractured cliffs the source of cometary dust jets? Insights from OSIRIS/Rosetta at 67P/Churyumov-Gerasimenko

Author: Frank Scholten, M. De Cecco, Imre Tóth, H. U. Keller, M. F. A'Hearn, M. A. Barucci, Ivano Bertini, Detlef Koschny, Nicolas Thomas, Michael Küppers, R. Rodrigo, Xian Shi, J. L. Bertaux, Stephen C. Lowry, J. B. Vincent, P. L. Lamy, Stefano Mottola, C. Güttler, X. Hu, L. M. Lara, V. Da Deppo, Holger Sierks, Marco Fulle, S. Fornasier, Wing-Huen Ip, Maurizio Pajola, Laurent Jorda, Géza Kovács, Matteo Massironi, Mohamed Ramy El-Maarry, Dennis Bodewits, F. Moreno, G. Cremonese, P. J. Gutierrez, Stubbe F. Hviid, Hans Rickman, Marc Hofmann, Francesco Marzari, Ekkehard Kührt, Giampiero Naletto, Stefano Debei, Cesare Barbieri, Zhong-Yi Lin, Olivier Groussin, Jörg Knollenberg, F. Preusker, P. Gutiérrez-Marquez, J.-R. Kramm, Sebastien Besse, Cecilia Tubiana, J. J. Lopez Moreno, B. J. R. Davidsson, S. Höfner, N. Oklay, Monica Lazzarin, Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Università degli Studi di Padova = University of Padua (Unipd), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Dipartimento di Fisica e Astronomia 'Galileo Galilei', Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), International Space Science Institute [Bern] (ISSI), Research and Scientific Support Department, ESTEC (RSSD), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk = Polish Academy of Sciences (PAN), Department of Physics and Astronomy [Uppsala], Uppsala University, Gauss Professor Akademie der Wissenschaften zu Göttingen, Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, 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), 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), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), CNR Institute for Photonics and Nanotechnologies (IFN), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Department of Industrial Engineering [Padova], University of Trento [Trento], Physikalisches Institut [Bern], Universität Bern [Bern] (UNIBE), INAF - Osservatorio Astronomico di Trieste (OAT), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), DLR Institute of Planetary Research, German Aerospace Center (DLR), Institute of Space Science [Taiwan], National Central University [Taiwan] (NCU), Department of Mechatronics, Optics and Mechanical Engineering Informatics (MOMEI), Budapest University of Technology and Economics [Budapest] (BME), European Space Astronomy Centre (ESAC), Agence Spatiale Européenne = European Space Agency (ESA), Centre for Astrophysics and Planetary Science [Canterbury] (CAPS), University of Kent [Canterbury], Department of Information Engineering [Padova] (DEI), Konkoly Observatory, Research Centre for Astronomy and Earth Sciences [Budapest], Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), European Space Agency, Centre National D'Etudes Spatiales (France), Agenzia Spaziale Italiana, Swedish National Space Agency, Ministerio de Economía y Competitividad (España), German Centre for Air and Space Travel, Max-Planck-Institut für Sonnensystemforschung (MPS), Universita degli Studi di Padova, European Space Agency (ESA)-European Space Agency (ESA), Consiglio Nazionale delle Ricerche [Roma] (CNR), Universität Bern [Bern], European Space Agency (ESA), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), and Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA)
Subjects: Comets: general, Comets: individual: 67P/Churyumov-Gerasimenko, Astronomy and Astrophysics, Space and Planetary Science, 67P/Churyumov-Gerasimenko, 010504 meteorology & atmospheric sciences, Comet, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], High resolution, comets: general / comets: individual: 67P/Churyumov-Gerasimenko, 01 natural sciences, Observational evidence, individual: 67P/Churyumov-Gerasimenko [Comets], 0103 physical sciences, Comets, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, biology, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Northern Hemisphere, Astronomy, general [Comets], biology.organism_classification, 13. Climate action, Osiris, Geology
Abstract: Context. Dust jets (i.e., fuzzy collimated streams of cometary material arising from the nucleus) have been observed in situ on all comets since the Giotto mission flew by comet 1P/Halley in 1986, and yet their formation mechanism remains unknown. Several solutions have been proposed involving either specific properties of the active areas or the local topography to create and focus the gas and dust flows. While the nucleus morphology seems to be responsible for the larger features, high resolution imagery has shown that broad streams are composed of many smaller jets (a few meters wide) that connect directly to the nucleus surface. Aims. We monitored these jets at high resolution and over several months to understand what the physical processes are that drive their formation and how this affects the surface. Methods. Using many images of the same areas with different viewing angles, we performed a 3-dimensional reconstruction of collimated jets and linked them precisely to their sources on the nucleus. Results. We show here observational evidence that the northern hemisphere jets of comet 67P/Churyumov-Gerasimenko arise from areas with sharp topographic changes and describe the physical processes involved. We propose a model in which active cliffs are the main source of jet-like features and therefore of the regions eroding the fastest on comets. We suggest that this is a common mechanism taking place on all comets., Astronomy and Astrophysics 587 (2016)##EDP Sciences##The support of the national funding agencies of Germany (DLR), France (CNES), Italy (ASI), Spain (MINECO), Sweden (SNSB), and the ESA Technical Directorate is gratefully acknowledged.
Published: 2016
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16. Sunset jets observed on comet 67P/Churyumov-Gerasimenko sustained by subsurface thermal lag

Author: Cesare Barbieri, J. J. López-Moreno, S. Höfner, Zhong-Yi Lin, M. Hofmann, Stubbe F. Hviid, Francesco Marzari, E. Kührt, M. Küppers, Géza Kovács, Rafael Rodrigo, Holger Sierks, Michael F. A'Hearn, X. Hu, Maurizio Pajola, Jürgen Blum, Monica Lazzarin, Pedro J. Gutiérrez, Sonia Fornasier, Stefano Debei, Xian Shi, Jean-Baptiste Vincent, C. Güttler, Jean-Loup Bertaux, Nilda Oklay, A. Gicquel, Ivano Bertini, J.-R. Kramm, L. M. Lara, Giampiero Naletto, Philippe Lamy, Detlef Koschny, Nicolas Thomas, Marco Fulle, V. Da Deppo, Stefano Mottola, Björn Davidsson, Mohamed Ramy El-Maarry, Hans Rickman, Cecilia Tubiana, Olivier Groussin, M. De Cecco, M. A. Barucci, Gabriele Cremonese, Wing-Huen Ip, Laurent Jorda, Dennis Bodewits, J. Knollenberg, H. U. Keller, Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Physikalisches Institut [Bern], Universität Bern [Bern], DLR Institute of Planetary Research, German Aerospace Center (DLR), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Universita degli Studi di Padova, 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), Institute of Astronomy [Taiwan] (IANCU), National Central University [Taiwan] (NCU), Dipartimento di Fisica e Astronomia 'Galileo Galilei', Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), International Space Science Institute [Bern] (ISSI), Research and Scientific Support Department, ESTEC (RSSD), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA)-European Space Agency (ESA), Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk = Polish Academy of Sciences (PAN), 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), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), CNR Institute for Photonics and Nanotechnologies (IFN), Consiglio Nazionale delle Ricerche [Roma] (CNR), Department of Physics and Astronomy [Uppsala], Uppsala University, Department of Industrial Engineering [Padova], University of Trento [Trento], INAF - Osservatorio Astronomico di Trieste (OAT), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Operations Department (ESAC), European Space Astronomy Centre (ESAC), Department of Information Engineering [Padova] (DEI), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Universität Bern [Bern] (UNIBE), Università degli Studi di Padova = University of Padua (Unipd), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), and Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES)
Subjects: Physics, 67P/Churyumov-Gerasimenko, Comets: individual: 67P/Churyumov-Gerasimenko, Thermal lag, Astronomy and Astrophysics, Space and Planetary Science, 010504 meteorology & atmospheric sciences, Thermal inertia, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Comet, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Astronomy, Astrophysics, Sunset, Solar illumination, 01 natural sciences, [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], 13. Climate action, 0103 physical sciences, Sublimation (phase transition), Water ice, comets, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: We present observations of sunset jets on comet 67P/Churyumov-Gerasimenko by Rosetta/OSIRIS camera. In late April 2015, when the comet was at a heliocentric distance of ~1.8 AU, clusters of dust jets that originated in the Ma'at region on the comet's small lobe were identified from multipleimages and were apparently sustained for about an hour beyond local sunset. Emanating from the shadowed nucleus, these jets became visible by solar illumination at their apparent sources up to only a few tens of meters above the nucleus surface. We investigate the plausibility of these jets as having been triggered by water ice sublimation and sustained by thermal lag in the subsurface beyond sunset. A general thermo-physical model was parameterized such that the thermal lag in the subsurface is consistent with the elapsed time of observation after sunset. It is found that the sublimation of water ice from a depth of 6 mm and with a low thermal inertia of 50 W m-2 K-1 s1/2 could explain the spatial pattern and evolution of the apparent sources, particularly their disappearance due to the eventual cooling of the subsurface. Our analysis suggests that these sunset jets were essentially day-side dust activities that continued after sunset. Specific observational conditions for the sunset jets constrain their possible sources to mostly within the less abrupt, dusty terrains. The uneven distribution of these jets is possibly related to subsurface inhomogeneities in the dusty area.
Published: 2016
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17. Temporal morphological changes in the Imhotep region of comet 67P/Churyumov-Gerasimenko

Author: Ekkehard Kührt, Simone Marchi, Björn Davidsson, M. A. Barucci, Olivier Groussin, Cecilia Tubiana, Sonia Fornasier, M. De Cecco, Matteo Massironi, Ivano Bertini, Nilda Oklay, Giampiero Naletto, Stubbe F. Hviid, Wing-Huen Ip, Laurent Jorda, Michael Küppers, Monica Lazzarin, Marco Fulle, C. Güttler, V. Da Deppo, Holger Sierks, Jean-Loup Bertaux, Mohamed Ramy El-Maarry, J. J. Lopez Moreno, Gabriele Cremonese, Antoine Pommerol, Pedro J. Gutiérrez, Rafael Rodrigo, Hans Rickman, J. B. Vincent, Géza Kovács, Philippe Lamy, M. F. A Hearn, Maurizio Pajola, J. Knollenberg, Stefano Debei, H. U. Keller, Detlef Koschny, Nicolas Thomas, Stephen C. Lowry, Stefano Mottola, J.-R. Kramm, Francesco Marzari, Sebastien Besse, Luisa Lara, A.-T. Auger, Imre Tóth, Cesare Barbieri, Laboratoire d'Astrophysique de Marseille (LAM), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Dipartimento di Fisica e Astronomia 'Galileo Galilei', Universita degli Studi di Padova, Centro de Astrobiologia [Madrid] (CAB), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA), International Space Science Institute [Bern] (ISSI), Research and Scientific Support Department, ESTEC (RSSD), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA)-European Space Agency (ESA), Department of Physics and Astronomy [Uppsala], Uppsala University, Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk = Polish Academy of Sciences (PAN), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, 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), 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), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Department of Industrial Engineering [Padova], CNR Institute for Photonics and Nanotechnologies (IFN), Consiglio Nazionale delle Ricerche [Roma] (CNR), University of Trento [Trento], Physikalisches Institut [Bern], Universität Bern [Bern], INAF - Osservatorio Astronomico di Trieste (OAT), Istituto Nazionale di Astrofisica (INAF), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Institute of Space Science [Taiwan], National Central University [Taiwan] (NCU), Operations Department (ESAC), European Space Astronomy Centre (ESAC), Centre for Astrophysics and Planetary Science [Canterbury] (CAPS), University of Kent [Canterbury], Solar System Exploration Research Virtual Institute (SSERVI), Southwest Research Institute [Boulder] (SwRI), INAF - Osservatorio Astronomico di Padova (OAPD), Department of Information Engineering [Padova] (DEI), Konkoly Observatory, Research Centre for Astronomy and Earth Sciences [Budapest], Hungarian Academy of Sciences (MTA)-Hungarian Academy of Sciences (MTA), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Università degli Studi di Padova = University of Padua (Unipd), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Universität Bern [Bern] (UNIBE), ITA, USA, GBR, FRA, DEU, and ESP
Subjects: 010504 meteorology & atmospheric sciences, Comet, FOS: Physical sciences, Astrophysics, 01 natural sciences, Observational period, Comets: individual: 67P/Churyumov-Gerasimenko – Comets: general – Methods: data analysis, Comets: general, Comets: individual: 67P/Churyumov-Gerasimenko, Methods: data analysis, Astronomy and Astrophysics, Space and Planetary Science, 0103 physical sciences, skin and connective tissue diseases, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Earth and Planetary Astrophysics (astro-ph.EP), biology, biology.organism_classification, 13. Climate action, Sublimation (phase transition), sense organs, Osiris, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Geology, Astrophysics - Earth and Planetary Astrophysics
Abstract: We report on the first major temporal morphological changes observed on the surface of the nucleus of comet 67P/Churyumov-Gerasimenko, in the smooth terrains of the Imhotep region. We use images of the OSIRIS cameras onboard Rosetta to follow the temporal changes from 24 May 2015 to 11 July 2015. The morphological changes observed on the surface are visible in the form of roundish features, which are growing in size from a given location in a preferential direction, at a rate of 5.6 - 8.1$\times$10$^{-5}$ m s$^{-1}$ during the observational period. The location where changes started and the contours of the expanding features are bluer than the surroundings, suggesting the presence of ices (H$_2$O and/or CO$_2$) exposed on the surface. However, sublimation of ices alone is not sufficient to explain the observed expanding features. No significant variations in the dust activity pattern are observed during the period of changes., 4 pages, 3 figures; Letter for Astronomy and Astrophysics: accepted
Published: 2015
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18. Comet 67P/Churyumov-Gerasimenko: Constraints on its origin from OSIRIS observations

Author: H. Rickman, S. Marchi, M. F. A’Hearn, C. Barbieri, M. R. El-Maarry, C. Güttler, W.-H. Ip, H. U. Keller, P. Lamy, F. Marzari, M. Massironi, G. Naletto, M. Pajola, H. Sierks, D. Koschny, R. Rodrigo, M. A. Barucci, J.-L. Bertaux, I. Bertini, G. Cremonese, V. Da Deppo, S. Debei, M. De Cecco, S. Fornasier, M. Fulle, O. Groussin, P. J. Gutiérrez, S. F. Hviid, L. Jorda, J. Knollenberg, J.-R. Kramm, E. Kührt, M. Küppers, L. M. Lara, M. Lazzarin, J. J. Lopez Moreno, H. Michalik, L. Sabau, N. Thomas, J.-B. Vincent, K.-P. Wenzel, Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk = Polish Academy of Sciences (PAN), Department of Physics and Astronomy [Uppsala], Uppsala University, Solar System Exploration Research Virtual Institute (SSERVI), Southwest Research Institute [Boulder] (SwRI), Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, Dipartimento di Fisica e Astronomia 'Galileo Galilei', Universita degli Studi di Padova, Physikalisches Institut [Bern], Universität Bern [Bern], Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Institute of Astronomy [Taiwan] (IANCU), National Central University [Taiwan] (NCU), Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), Dipartimento di Geoscienze [Padova], Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Department of Industrial Engineering [Padova], CNR Institute for Photonics and Nanotechnologies (IFN), Consiglio Nazionale delle Ricerche [Roma] (CNR), Research and Scientific Support Department, ESTEC (RSSD), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA)-European Space Agency (ESA), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), International Space Science Institute [Bern] (ISSI), 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), 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), INAF - Osservatorio Astronomico di Padova (OAPD), Istituto Nazionale di Astrofisica (INAF), Università degli Studi di Trento (UNITN), INAF - Osservatorio Astronomico di Trieste (OAT), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), DLR Institute of Planetary Research, German Aerospace Center (DLR), Operations Department (ESAC), European Space Astronomy Centre (ESAC), Institut für Datentechnik und Kommunikationsnetze, Instituto Nacional de Técnica Aeroespacial (INTA), ITA, USA, GBR, FRA, DEU, ESP, Università degli Studi di Padova = University of Padua (Unipd), Universität Bern [Bern] (UNIBE), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), National Research Council of Italy | Consiglio Nazionale delle Ricerche (CNR), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), and Consejo Superior de Investigaciones Científicas [Madrid] (CSIC)-Instituto Nacional de Técnica Aeroespacial (INTA)
Subjects: 67P/Churyumov-Gerasimenko, Solar System, Planetesimal, Comet, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], FOS: Physical sciences, Contact binary, Astrophysics, Parent body, medicine, collisional evolution, comets, planetesimals, Physics, Earth and Planetary Astrophysics (astro-ph.EP), Comets: individual: 67P/Churyumov-Gerasimenko, Astronomy and Astrophysics, Space and Planetary Science, Accretion (astrophysics), medicine.anatomical_structure, Comet 67P/Churyumov-Gerasimenko, 13. Climate action, Formation and evolution of the Solar System, Nucleus, Astrophysics - Earth and Planetary Astrophysics
Abstract: One of the main aims of the ESA Rosetta mission is to study the origin of the solar system by exploring comet 67P/Churyumov-Gerasimenko at close range. In this paper we discuss the origin and evolution of comet 67P/Churyumov-Gerasimenko in relation to that of comets in general and in the framework of current solar system formation models. We use data from the OSIRIS scientific cameras as basic constraints. In particular, we discuss the overall bi-lobate shape and the presence of key geological features, such as layers and fractures. We also treat the problem of collisional evolution of comet nuclei by a particle-in-a-box calculation for an estimate of the probability of survival for 67P/Churyumov-Gerasimenko during the early epochs of the solar system. We argue that the two lobes of the 67P/Churyumov-Gerasimenko nucleus are derived from two distinct objects that have formed a contact binary via a gentle merger. The lobes are separate bodies, though sufficiently similar to have formed in the same environment. An estimate of the collisional rate in the primordial, trans-planetary disk shows that most comets of similar size to 67P/Churyumov-Gerasimenko are likely collisional fragments, although survival of primordial planetesimals cannot be excluded. A collisional origin of the contact binary is suggested, and the low bulk density of the aggregate and abundance of volatile species show that a very gentle merger must have occurred. We thus consider two main scenarios: the primordial accretion of planetesimals, and the re-accretion of fragments after an energetic impact onto a larger parent body. We point to the primordial signatures exhibited by 67P/Churyumov-Gerasimenko and other comet nuclei as critical tests of the collisional evolution., Comment: Accepted, to appear on Astronomy & Astrophysics
Published: 2015
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19. Intuitive and Adaptive Robotic Arm Manipulation using the Leap Motion Controller

Author: Bassily, D., Georgoulas, C., Güttler, J. and Linner, T., Bock, T.
Subjects: ddc
Abstract: Robotics provide an efficient approach in the development of assistive devices, due to their enhanced functionality. Statistics predict that by 2035, half of the population in Germany is going to be older than fifty, every third person even over 60. These ageing societies face numerous challenges in performing simple tasks in Activities of Daily Living “ADLs”. Increasingly, a lot of research is being focused on Ambient Assisted Living “AAL” which presents a new approach that promises to address the needs of elderly people. An important goal of AAL is to contribute to the quality of life of the elderly and handicapped people and help them to maintain an independent lifestyle. The introduction of robotics and technology-supported environments will play a huge role in allowing elderly and physically impaired people to keep living a self-determined, independent life in their familiar surroundings. In this paper, the implementation of a novel intuitive and adaptive manipulation scheme is proposed, by developing a human-machine communication interface between the Leap Motion controller and the 6-DOF Jaco robotic arm. An algorithm is developed to allow an optimum mapping between the user hand movement, tracked by the Leap Motion controller, and the Jaco arm. The system should allow for a more natural human-computer interaction and a smooth manipulation of the robotic arm, by constantly adapting to the user hand tremor or shake. The implementation would specially enhance the quality of living, especially for people with upper limb problems, and would support them in performing some of the essential Activities of Daily Living “ADLs”. The applications of this human-robot interaction will be discussed in relation with Ambient Assisted Living, where some use case scenarios will be introduced.
Published: 2013

20. Detection of exposed H2O ice on the nucleus of comet 67P/Churyumov-Gerasimenko

Author: Ivano Bertini, Ekkehard Kührt, Michael Küppers, Cesare Barbieri, Monica Lazzarin, P. L. Lamy, S. Fornasier, Gianrico Filacchione, Bernard Schmitt, Antoine Pommerol, Laurent Jorda, J. D. P. Deshapriya, Matteo Massironi, Gabriele Arnold, Holger Sierks, Dominique Bockelée-Morvan, Stubbe F. Hviid, C. Güttler, S. Fonti, F. Merlin, C. Leyrat, Cecilia Tubiana, J. B. Vincent, V. Da Deppo, A. Guilbert-Lepoutre, J.-R. Kramm, Marco Fulle, Mauro Ciarniello, Mohamed Ramy El-Maarry, Olivier Groussin, Detlef Koschny, Hans Rickman, F. Mancarella, L. M. Lara, Nicolas Thomas, M. T. Capria, N. Oklay, M. A. Barucci, W-H. Ip, Stéphane Erard, Maurizio Pajola, Priscilla Cerroni, G. Cremonese, Clement Feller, D. Perna, Andrea Raponi, Eric Quirico, J. J. Lopez Moreno, C. de Sanctis, Stefano Mottola, P. Drossart, B. J. R. Davidsson, Batiste Rousseau, Ernesto Palomba, R. Rodrigo, M. F. A'Hearn, J. L. Bertaux, Horst Uwe Keller, Pedro Hasselmann, Jörg Knollenberg, Marcello Fulchignoni, David Kappel, Fabrizio Capaccioni, Federico Tosi, Giampiero Naletto, Francesco Marzari, 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), Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), Istituto Nazionale di Astrofisica (INAF), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Physikalisches Institut [Bern], Universität Bern [Bern] (UNIBE), Dipartimento di Geoscienze [Padova], Università degli Studi di Padova = University of Padua (Unipd), Univers, Transport, Interfaces, Nanostructures, Atmosphère et environnement, Molécules (UMR 6213) (UTINAM), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), Dipartimento di Fisica e Astronomia 'Galileo Galilei', Laboratoire d'Astrophysique de Marseille (LAM), Aix Marseille Université (AMU)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS), International Space Science Institute [Bern] (ISSI), European Space Research and Technology Centre (ESTEC), Agence Spatiale Européenne = European Space Agency (ESA), Space Research Centre of Polish Academy of Sciences (CBK), Polska Akademia Nauk = Polish Academy of Sciences (PAN), Department of Physics and Astronomy [Uppsala], Uppsala University, Institut für Geophysik und Extraterrestrische Physik [Braunschweig] (IGEP), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Department of Astronomy [College Park], University of Maryland [College Park], University of Maryland System-University of Maryland System, DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), 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), INAF - Osservatorio Astronomico di Padova (OAPD), Department of Information Engineering [Padova] (DEI), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Department of Physics [Lecce], Università del Salento [Lecce], INAF - Osservatorio Astronomico di Trieste (OAT), Institute of Space Science [Taiwan], National Central University [Taiwan] (NCU), Operations Department (ESAC), European Space Astronomy Centre (ESAC), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), Instituto de Astrofísica de Andalucía (IAA), Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), NASA Ames Research Center (ARC), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national des sciences de l'Univers (INSU - CNRS)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP )-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes [2016-2019] (UGA [2016-2019]), Ministerio de Economía y Competitividad (España), European Space Agency, Swedish National Space Agency, Agenzia Spaziale Italiana, German Centre for Air and Space Travel, Centre National D'Etudes Spatiales (France), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC), Max-Planck-Institut für Sonnensystemforschung (MPS), Universität Bern [Bern], Universita degli Studi di Padova, European Space Agency (ESA), Polska Akademia Nauk (PAN), Technische Universität Braunschweig [Braunschweig], IMPEC - LATMOS, European Space Agency (ESA)-European Space Agency (ESA), Consejo Superior de Investigaciones Científicas [Spain] (CSIC), Centre National d'Études Spatiales [Toulouse] (CNES)-Université Grenoble Alpes (UGA)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire des Sciences de l'Univers de Grenoble (OSUG), Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Université Joseph Fourier - Grenoble 1 (UJF)-Centre National de la Recherche Scientifique (CNRS), California Institute of Technology (CALTECH)-NASA, Université de Franche-Comté (UFC)-Centre National de la Recherche Scientifique (CNRS)-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)-Aix Marseille Université (AMU)-Centre National d'Études Spatiales [Toulouse] (CNES), ITA, USA, FRA, DEU, ESP, TWN, NLD, POL, SWE, and CHE
Subjects: 67P/Churyumov-Gerasimenko, 010504 meteorology & atmospheric sciences, Comet, Data analysis, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Techniques: image processing, Context (language use), 01 natural sciences, Spectral line, Photometry, individual: 67P/Churyumov-Gerasimenko [Comets], Methods: data analysis, 0103 physical sciences, Comets, medicine, image processing [Techniques], data analysis [Methods], Techniques: imaging spectroscopy, 010303 astronomy & astrophysics, Spectroscopy, 0105 earth and related environmental sciences, Comets: individual: 67P/Churyumov-Gerasimenko, Physics, biology, Pixel, Spots, Techniques: photometric, imaging spectroscopy [Techniques], photometric [Techniques], Astronomy, Astronomy and Astrophysics, comets: individual: 67P/Churyumov-Gerasimenko – techniques: imaging spectroscopy – techniques: photometric – techniques: image processing – methods: data analysis, biology.organism_classification, comets: individual: 67P/Churyumov-Gerasimenko / techniques: imaging spectroscopy / techniques: photometric / techniques: image processing / methods: data analysis, medicine.anatomical_structure, Space and Planetary Science, Absorption band, Osiris, Nucleus
Abstract: [Context] Since the orbital insertion of the Rosetta spacecraft, comet 67P/Churyumov-Gerasimenko (67P) has been mapped by OSIRIS camera and VIRTIS spectro-imager, producing a huge quantity of images and spectra of the comet's nucleus., [Aims] The aim of this work is to search for the presence of HO on the nucleus which, in general, appears very dark and rich in dehydrated organic material. After selecting images of the bright spots which could be good candidates to search for HO ice, taken at high resolution by OSIRIS, we check for spectral cubes of the selected coordinates to identify these spots observed by VIRTIS., [Methods] The selected OSIRIS images were processed with the OSIRIS standard pipeline and corrected for the illumination conditions for each pixel using the Lommel-Seeliger disk law. The spots with higher I/F were selected and then analysed spectrophotometrically and compared with the surrounding area. We selected 13 spots as good targets to be analysed by VIRTIS to search for the 2 μm absorption band of water ice in the VIRTIS spectral cubes., [Results] Out of the 13 selected bright spots, eight of them present positive HO ice detection on the VIRTIS data. A spectral analysis was performed and the approximate temperature of each spot was computed. The HO ice content was confirmed by modeling the spectra with mixing (areal and intimate) of HO ice and dark terrain, using Hapke's radiative transfer modeling. We also present a detailed analysis of the detected spots., The support of the national funding agencies of Germany (DLR), France (CNES), Italy (ASI), Spain (MEC), Sweden (SNSB), and the ESA Technical Directorate is gratefully acknowledged.
Published: 2016
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21. Grainyhead like 3 – a newly identified TNFalpha regulated transcription factor – is regulated by the Src kinases & NO

Author: M Lukosz, C Güttler, J Haendeler, and Joachim Altschmied
Subjects: integumentary system, Kinase, Activator (genetics), Cell migration, Cell Biology, Biology, Biochemistry, Molecular biology, Nitric oxide, Vascular endothelial growth factor, chemistry.chemical_compound, FYN, chemistry, Meeting Abstract, Molecular Biology, Transcription factor, Proto-oncogene tyrosine-protein kinase Src
Abstract: One major independent risk factor of cardiovascular diseases (CAD) is aging. Therefore, it is important to understand vascular aging on a cellular level. It is known that TNFalpha is increased in serum of CAD patients, induces senescence and apoptosis of endothelial cells (EC) and decreases their migratory capacity. Recently, we discovered the transcription factor Grainyhead like 3 (GRHL3) as a TNFalpha regulated gene. GRHL3 -/- mice demonstrated defects in cell migration. Therefore, the aim of our study was to investigate the role of GRHL3 in EC migration and the underlying mechanisms. After verifying expression of GRHL3 in EC, GRHL3 was cloned and overexpressed in EC. GRHL3 induced migration to a similar degree as vascular endothelial growth factor (VEGF). To get insights in the underlying mechanisms, we analyzed a known VEGF-induced migration activator, endothelial nitric oxide synthase (eNOS). eNOS phosphorylation on S1179 was increased upon overexpression of GRHL3, suggesting that GRHL3 increased EC cell migration through a nitric oxide (NO) dependent pathway. To determine whether a potentional positive feedback loop of nitric oxide (NO) and GRHL3 exists, we next tested the effect of NO on endogenous GRHL3 expression by real time PCR. Incubation with the NO donor papanonoate dramatically increased GRHL3 mRNA expression (papanonoate: 3.75-fold +/- 1.34 of control). Furthermore, decreased migratory capacity of senescent EC concomitant with an increase in Src kinase activity has been shown. To analyze whether Src has an influence on GRHL3, we determined the nuclear levels of this promigratory transcription factor in mouse embryonic fibroblasts (MEF), deficient for Src, Fyn and Yes (SFY -/-). A higher concentration of GRHL3 protein was observed in nuclear extracts of SFY -/- MEF. To demonstrate that the Src kinase family is indeed a negative regulator of GRHL3 expression in EC, we treated the cells with the Src kinase family inhibitor PP2 and analyzed expression of GRHL3. Indeed, expression of GRHL3 was dramatically increased by PP2 (PP2: 4.50-fold +/- 1.72 of control). In conclusion, GRHL3 is an important inducer of EC migration mediated through activation of eNOS/NO. NO in turn induces GRHL3 expression, suggesting a positive feedback loop. In addition, the Src kinase family negatively regulates endogenous GRHL3.
Published: 2009
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22. Experimental Phase Function and Degree of Linear Polarization Curves of Millimeter-sized Cosmic Dust Analogs.

Author: O. Muñoz, F. Moreno, J. C. Gómez-Martín, F. Vargas-Martín, D. Guirado, J. L. Ramos, I. Bustamante, I. Bertini, E. Frattin, J. Markannen, C. Tubiana, M. Fulle, C. Güttler, H. Sierks, A. Rotundi, V. Della Corte, S. Ivanovski, V. V. Zakharov, D. Bockelée-Morvan, and J. Blum
Published: 2020
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23. XII. Gassend oder Gassendi?

Author: C. Güttler
Subjects: Philosophy
Abstract: n/a
Published: 1897

24. Zwei unbekannte Dialoge Giordano Bruno’s nebst biographischen Notizen

Author: C. Güttler
Subjects: Philosophy
Published: 1893
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25. Models of Rosetta/OSIRIS 67P Dust Coma Phase Function.

Author: F. Moreno, D. Guirado, O. Muñoz, I. Bertini, C. Tubiana, C. Güttler, M. Fulle, A. Rotundi, V. Della Corte, S. L. Ivanovski, G. Rinaldi, D. Bockelée-Morvan, V. V. Zakharov, J. Agarwal, S. Mottola, I. Toth, E. Frattin, L. M. Lara, P. J. Gutiérrez, and Z. Y. Lin
Published: 2018
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26. Changes in Functional Connectivity Relate to Modulation of Cognitive Control by Subthalamic Stimulation.

Author: Achtzehn J, Grospietsch F, Horn A, Güttler C, Horn A, Marcelino ALA, Wenzel G, Schneider GH, Neumann WJ, and Kühn AA
Subjects: Humans, Male, Middle Aged, Female, Aged, Executive Function physiology, Connectome, Reaction Time physiology, Neural Pathways physiopathology, Neural Pathways diagnostic imaging, Neural Pathways physiology, Deep Brain Stimulation methods, Subthalamic Nucleus diagnostic imaging, Subthalamic Nucleus physiopathology, Subthalamic Nucleus physiology, Parkinson Disease therapy, Parkinson Disease physiopathology, Parkinson Disease diagnostic imaging, Magnetic Resonance Imaging, Psychomotor Performance physiology
Abstract: Subthalamic (STN) deep brain stimulation (DBS) in Parkinson's disease (PD) patients not only improves kinematic parameters of movement but also modulates cognitive control in the motor and non-motor domain, especially in situations of high conflict. The objective of this study was to investigate the relationship between DBS-induced changes in functional connectivity at rest and modulation of response- and movement inhibition by STN-DBS in a visuomotor task involving high conflict. During DBS ON and OFF conditions, we conducted a visuomotor task in 14 PD patients who previously underwent resting-state functional MRI (rs-fMRI) acquisitions DBS ON and OFF as part of a different study. In the task, participants had to move a cursor with a pen on a digital tablet either toward (automatic condition) or in the opposite direction (controlled condition) of a target. STN-DBS induced modulation of resting-state functional connectivity (RSFC) as a function of changes in behavior ON versus OFF DBS was estimated using link-wise network-based statistics. Behavioral results showed diminished reaction time adaptation and higher pen-to-target movement velocity under DBS. Reaction time reduction was associated with attenuated functional connectivity between cortical motor areas, basal ganglia, and thalamus. On the other hand, increased movement velocity ON DBS was associated with stronger pallido-thalamic connectivity. These findings suggest that decoupling of a motor cortico-basal ganglia network underlies impaired inhibitory control in PD patients undergoing subthalamic DBS and highlight the concept of functional network modulation through DBS., (© 2024 The Author(s). Human Brain Mapping published by Wiley Periodicals LLC.)
Published: 2024
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27. Effects of the Tovertafel ® on apathy, social interaction and social activity of people with dementia in long-term inpatient care: results of a non-controlled within-subject-design study.

Author: Konrad R, Güttler C, Öhl N, Heidl C, Scholz S, and Bauer C
Abstract: Introduction: Tovertafel ® is a VR-based serious game for dementia care (SGDC) that aims to stimulate residents affected by dementia in nursing homes, promote social and cognitive skills and reduce apathy. The aim of this study is to investigate the effects of using Tovertafel ® on apathy, social interaction and social activity of people with dementia (PWD) in long-term inpatient care in Germany., Methods: In this monocentric intervention study, 25 residents of an inpatient long-term care facility with moderate or severe dementia had two weekly applications of Tovertafel ® over a period of 8 weeks. Effects on the residents' social interaction and activity were recorded before (T1), during (T2) and 1 h after (T3) each intervention using the Engagement of a Person with Dementia Scale (EPWDS). The degree of apathy was assessed using the Apathy Evaluation Scale (AES). Effects of Tovertafel ® were examined using a simple repeated measures analysis of variance (ANOVA)., Results: Thirteen residents with moderate (52%) and 12 residents with severe dementia (48%) were included. Results showed that residents' apathy changed over the course of the trial and was partially reduced. ANOVA revealed significant changes in the positive expression of social participation in the overall group between individual observation times ( p < 0.001; T1: MW = 2.67, SD = 1.352; T2: MW = 3.66, SD = 1.365; T3: MW = 3.10, SD = 1.300) and a significantly lower negative expression of social participation at T2 (MW = 1.09, SD = 0.358) than at T1 (MW = 1.19, SD = 0.579; p = 0.028). There was a significantly higher positive expression of behavioral involvement in the overall group at T3 (MW = 1.17, SD = 0.552) than at T1 ( p = 0.003) or T2 ( p = 0.045). Analyses did not find any significant interaction between observation times and degree of dementia., Discussion: Results of the study show that the use of Tovertafel ® over a period of 2 months had significant effects on apathy, social activity and social interaction in people with moderate or severe dementia. Symptoms of apathy could be reduced and social interaction and activity increased. However, due to limitations of the study design and special circumstances of the COVID-19 pandemic situation, findings might be overestimated and must be interpreted with care. Further research is necessary., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Konrad, Güttler, Öhl, Heidl, Scholz and Bauer.)
Published: 2024
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28. External Validation and Retraining of DeepBleed: The First Open-Source 3D Deep Learning Network for the Segmentation of Spontaneous Intracerebral and Intraventricular Hemorrhage.

Author: Cao H, Morotti A, Mazzacane F, Desser D, Schlunk F, Güttler C, Kniep H, Penzkofer T, Fiehler J, Hanning U, Dell'Orco A, and Nawabi J
Abstract: Background: The objective of this study was to assess the performance of the first publicly available automated 3D segmentation for spontaneous intracerebral hemorrhage (ICH) based on a 3D neural network before and after retraining., Methods: We performed an independent validation of this model using a multicenter retrospective cohort. Performance metrics were evaluated using the dice score (DSC), sensitivity, and positive predictive values (PPV). We retrained the original model (OM) and assessed the performance via an external validation design. A multivariate linear regression model was used to identify independent variables associated with the model's performance. Agreements in volumetric measurements and segmentation were evaluated using Pearson's correlation coefficients (r) and intraclass correlation coefficients (ICC), respectively. With 1040 patients, the OM had a median DSC, sensitivity, and PPV of 0.84, 0.79, and 0.93, compared to thoseo f 0.83, 0.80, and 0.91 in the retrained model (RM). However, the median DSC for infratentorial ICH was relatively low and improved significantly after retraining, at p < 0.001. ICH volume and location were significantly associated with the DSC, at p < 0.05. The agreement between volumetric measurements (r > 0.90, p > 0.05) and segmentations (ICC ≥ 0.9, p < 0.001) was excellent., Conclusion: The model demonstrated good generalization in an external validation cohort. Location-specific variances improved significantly after retraining. External validation and retraining are important steps to consider before applying deep learning models in new clinical settings.
Published: 2023
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29. Interpretable surface-based detection of focal cortical dysplasias: a Multi-centre Epilepsy Lesion Detection study.

Author: Spitzer H, Ripart M, Whitaker K, D'Arco F, Mankad K, Chen AA, Napolitano A, De Palma L, De Benedictis A, Foldes S, Humphreys Z, Zhang K, Hu W, Mo J, Likeman M, Davies S, Güttler C, Lenge M, Cohen NT, Tang Y, Wang S, Chari A, Tisdall M, Bargallo N, Conde-Blanco E, Pariente JC, Pascual-Diaz S, Delgado-Martínez I, Pérez-Enríquez C, Lagorio I, Abela E, Mullatti N, O'Muircheartaigh J, Vecchiato K, Liu Y, Caligiuri ME, Sinclair B, Vivash L, Willard A, Kandasamy J, McLellan A, Sokol D, Semmelroch M, Kloster AG, Opheim G, Ribeiro L, Yasuda C, Rossi-Espagnet C, Hamandi K, Tietze A, Barba C, Guerrini R, Gaillard WD, You X, Wang I, González-Ortiz S, Severino M, Striano P, Tortora D, Kälviäinen R, Gambardella A, Labate A, Desmond P, Lui E, O'Brien T, Shetty J, Jackson G, Duncan JS, Winston GP, Pinborg LH, Cendes F, Theis FJ, Shinohara RT, Cross JH, Baldeweg T, Adler S, and Wagstyl K
Subjects: Humans, Retrospective Studies, Magnetic Resonance Imaging methods, Machine Learning, Malformations of Cortical Development complications, Malformations of Cortical Development diagnostic imaging, Epilepsy diagnostic imaging, Epilepsies, Partial diagnostic imaging
Abstract: One outstanding challenge for machine learning in diagnostic biomedical imaging is algorithm interpretability. A key application is the identification of subtle epileptogenic focal cortical dysplasias (FCDs) from structural MRI. FCDs are difficult to visualize on structural MRI but are often amenable to surgical resection. We aimed to develop an open-source, interpretable, surface-based machine-learning algorithm to automatically identify FCDs on heterogeneous structural MRI data from epilepsy surgery centres worldwide. The Multi-centre Epilepsy Lesion Detection (MELD) Project collated and harmonized a retrospective MRI cohort of 1015 participants, 618 patients with focal FCD-related epilepsy and 397 controls, from 22 epilepsy centres worldwide. We created a neural network for FCD detection based on 33 surface-based features. The network was trained and cross-validated on 50% of the total cohort and tested on the remaining 50% as well as on 2 independent test sites. Multidimensional feature analysis and integrated gradient saliencies were used to interrogate network performance. Our pipeline outputs individual patient reports, which identify the location of predicted lesions, alongside their imaging features and relative saliency to the classifier. On a restricted 'gold-standard' subcohort of seizure-free patients with FCD type IIB who had T1 and fluid-attenuated inversion recovery MRI data, the MELD FCD surface-based algorithm had a sensitivity of 85%. Across the entire withheld test cohort the sensitivity was 59% and specificity was 54%. After including a border zone around lesions, to account for uncertainty around the borders of manually delineated lesion masks, the sensitivity was 67%. This multicentre, multinational study with open access protocols and code has developed a robust and interpretable machine-learning algorithm for automated detection of focal cortical dysplasias, giving physicians greater confidence in the identification of subtle MRI lesions in individuals with epilepsy., (© The Author(s) 2022. Published by Oxford University Press on behalf of the Guarantors of Brain.)
Published: 2022
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30. Tablets as an Option for Telemedicine-Evaluation of Diagnostic Performance and Efficiency in Intracranial Arterial Aneurysm Detection.

Author: Can E, Gebert P, Sodemann EB, Kolck J, Walter-Rittel TC, Maaßen A, Güttler C, Stöckel J, Bohner G, and Böning G
Abstract: Purpose: To evaluate a commercially available mobile device for the highly specialized task of detection of intracranial arterial aneurysm in telemedicine. Methods: Six radiologists with three different levels of experience retrospectively interpreted 60 computed tomography (CT) angiographies for the presence of intracranial arterial aneurysm, among them 30 cases with confirmed positive findings. Each radiologist reviewed the angiography datasets twice: once on a dedicated medical-grade workstation and on a commercially available mobile consumer-grade tablet with an interval of 3 months. Diagnostic performance, reading efficiency and subjective scorings including diagnostic confidence were analyzed and compared. Results: Diagnostic performance was comparable on both devices regardless of readers' experience, and no significant differences in sensitivity (66-87.5%) and specificity (79.4-87%) were found. Results obtained with tablets and medical workstations were also comparable in terms of subjective assessment across all reader groups. Conclusions: There was no significant difference between tablet and workstation readings of angiography datasets for the presence of intracranial arterial aneurysm. Sensitivity, specificity, efficiency and subjective scorings were similar with the two devices for all three reader groups. While medical workstations are 10 times more expensive, tablets allow higher mobility especially for radiologists on call.
Published: 2022
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31. A translational perspective on pathophysiological changes of oscillatory activity in dystonia and parkinsonism.

Author: Rauschenberger L, Güttler C, Volkmann J, Kühn AA, Ip CW, and Lofredi R
Subjects: Animals, Deep Brain Stimulation, Dystonia therapy, Dystonic Disorders, Movement Disorders pathology, Parkinsonian Disorders
Abstract: Intracerebral recordings from movement disorders patients undergoing deep brain stimulation have allowed the identification of pathophysiological patterns in oscillatory activity that correlate with symptom severity. Changes in oscillatory synchrony occur within and across brain areas, matching the classification of movement disorders as network disorders. However, the underlying mechanisms of oscillatory changes are difficult to assess in patients, as experimental interventions are technically limited and ethically problematic. This is why animal models play an important role in neurophysiological research of movement disorders. In this review, we highlight the contributions of translational research to the mechanistic understanding of pathological changes in oscillatory activity, with a focus on parkinsonism and dystonia, while addressing the limitations of current findings and proposing possible future directions., (Copyright © 2022 The Authors. Published by Elsevier Inc. All rights reserved.)
Published: 2022
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32. Lead-OR: A multimodal platform for deep brain stimulation surgery.

Author: Oxenford S, Roediger J, Neudorfer C, Milosevic L, Güttler C, Spindler P, Vajkoczy P, Neumann WJ, Kühn A, and Horn A
Subjects: Electrodes, Implanted, Humans, Magnetic Resonance Imaging methods, Microelectrodes, Neuroimaging methods, Retrospective Studies, Deep Brain Stimulation methods
Abstract: Background: Deep brain stimulation (DBS) electrode implant trajectories are stereotactically defined using preoperative neuroimaging. To validate the correct trajectory, microelectrode recordings (MERs) or local field potential recordings can be used to extend neuroanatomical information (defined by MRI) with neurophysiological activity patterns recorded from micro- and macroelectrodes probing the surgical target site. Currently, these two sources of information (imaging vs. electrophysiology) are analyzed separately, while means to fuse both data streams have not been introduced., Methods: Here, we present a tool that integrates resources from stereotactic planning, neuroimaging, MER, and high-resolution atlas data to create a real-time visualization of the implant trajectory. We validate the tool based on a retrospective cohort of DBS patients (N = 52) offline and present single-use cases of the real-time platform., Results: We establish an open-source software tool for multimodal data visualization and analysis during DBS surgery. We show a general correspondence between features derived from neuroimaging and electrophysiological recordings and present examples that demonstrate the functionality of the tool., Conclusions: This novel software platform for multimodal data visualization and analysis bears translational potential to improve accuracy of DBS surgery. The toolbox is made openly available and is extendable to integrate with additional software packages., Funding: Deutsche Forschungsgesellschaft (410169619, 424778381), Deutsches Zentrum für Luft- und Raumfahrt (DynaSti), National Institutes of Health (2R01 MH113929), and Foundation for OCD Research (FFOR)., Competing Interests: SO, JR, CN, LM, CG, PS, PV, WN No competing interests declared, AK Reports personal fees from Medtronic, Boston Scientific, Abbott, Teva, Ipsen and Stadapharm, all outside the submitted work, AH Reports lecture fee for Boston Scientific outside the submitted work, (© 2022, Oxenford et al.)
Published: 2022
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33. The CoPhyLab comet-simulation chamber.

Author: Kreuzig C, Kargl G, Pommerol A, Knollenberg J, Lethuillier A, Molinski NS, Gilke T, Bischoff D, Feller C, Kührt E, Sierks H, Hänni N, Capelo H, Güttler C, Haack D, Otto K, Kaufmann E, Schweighart M, Macher W, Tiefenbacher P, Gundlach B, and Blum J
Abstract: The Comet Physics Laboratory (CoPhyLab) is an international research program to study the physical properties of cometary analog materials under simulated space conditions. The project is dedicated to studying, with the help of multiple instruments and the different expertise and background from the different partners, the physics of comets, including the processes inside cometary nuclei, the activity leading to the ejection of dust and gas, and the sub-surface and surface evolution of cometary nuclei when exposed to solar illumination. CoPhyLab will provide essential information on the formation and evolution of comets and insights into the origins of primitive Solar System bodies. To this end, we constructed a new laboratory that hosts several small-scale experiments and a large-scale comet-simulation chamber (L-Chamber). This chamber has been designed and constructed to host ice-dust samples with a diameter of up to 250 mm and a variable height between 100 and 300 mm. The cometary-analog samples will be kept at temperatures below 120 K and pressures around 10 -6 mbar to ensure cometary-like conditions. In total, 14 different scientific instruments are attached to the L-Chamber to study the temporal evolution of the physical properties of the sample under different insolation conditions. Due to the implementation of a scale inside the L-Chamber that can measure weight changes of the samples with high precision, the cooling system is mechanically decoupled from the sample holder and cooling of the samples occurs by radiation only. The constructed chamber allows us to conduct uninterrupted experiments at low temperatures and pressures up to several weeks.
Published: 2021
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34. Reply to: "Levodopa-Induced Dyskinesia Is Mediated by Cortical Gamma Oscillations in Experimental Parkinsonism".

Author: Güttler C, Nikulin VV, and van Riesen C
Subjects: Humans, Levodopa adverse effects, Dyskinesia, Drug-Induced etiology, Parkinsonian Disorders chemically induced, Parkinsonian Disorders drug therapy
Published: 2021
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35. Levodopa-Induced Dyskinesia Are Mediated by Cortical Gamma Oscillations in Experimental Parkinsonism.

Author: Güttler C, Altschüler J, Tanev K, Böckmann S, Haumesser JK, Nikulin VV, Kühn AA, and van Riesen C
Subjects: Animals, Antiparkinson Agents adverse effects, Disease Models, Animal, Levodopa adverse effects, Oxidopamine toxicity, Rats, Dyskinesia, Drug-Induced etiology, Parkinson Disease, Parkinsonian Disorders chemically induced, Parkinsonian Disorders drug therapy
Abstract: Background: Levodopa is the most efficacious drug in the symptomatic therapy of motor symptoms in Parkinson's disease (PD); however, long-term treatment is often complicated by troublesome levodopa-induced dyskinesia (LID). Recent evidence suggests that LID might be related to increased cortical gamma oscillations., Objective: The objective of this study was to test the hypothesis that cortical high-gamma network activity relates to LID in the 6-hydroxydopamine model and to identify new biomarkers for adaptive deep brain stimulation (DBS) therapy in PD., Methods: We recorded and analyzed primary motor cortex (M1) electrocorticogram data and motor behavior in freely moving 6-OHDA lesioned rats before and during a daily treatment with levodopa for 3 weeks. The results were correlated with the abnormal involuntary movement score (AIMS) and used for generalized linear modeling (GLM)., Results: Levodopa reverted motor impairment, suppressed beta activity, and, with repeated administration, led to a progressive enhancement of LID. Concurrently, we observed a highly significant stepwise amplitude increase in finely tuned gamma (FTG) activity and gamma centroid frequency. Whereas AIMS and FTG reached their maximum after the 4th injection and remained on a stable plateau thereafter, the centroid frequency of the FTG power continued to increase thereafter. Among the analyzed gamma activity parameters, the fraction of longest gamma bursts showed the strongest correlation with AIMS. Using a GLM, it was possible to accurately predict AIMS from cortical recordings., Conclusions: FTG activity is tightly linked to LID and should be studied as a biomarker for adaptive DBS. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society., (© 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.)
Published: 2021
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36. Global-scale brittle plastic rheology at the cometesimals merging of comet 67P/Churyumov-Gerasimenko.

Author: Franceschi M, Penasa L, Massironi M, Naletto G, Ferrari S, Fondriest M, Bodewits D, Güttler C, Lucchetti A, Mottola S, Pajola M, Toth I, Deller J, Sierks H, and Tubiana C
Abstract: Observations of comet nuclei indicate that the main constituent is a mix of ice and refractory materials characterized by high porosity (70-75%) and low bulk strength (10 -4 -10 -6 MPa); however, the nature and physical properties of these materials remain largely unknown. By combining surface inspection of comet 67P/Churyumov-Gerasimenko and three-dimensional (3D) modeling of the independent concentric sets of layers that make up the structure of its two lobes, we provide clues about the large-scale rheological behavior of the nucleus and the kinematics of the impact that originated it. Large folds in the layered structure indicate that the merging of the two cometesimals involved reciprocal motion with dextral strike-slip kinematics that bent the layers in the contact area without obliterating them. Widespread long cracks and the evidence of relevant mass loss in absence of large density variations within the comet's body testify that large-scale deformation occurred in a brittle-plastic regime and was accommodated through folding and fracturing. Comparison of refined 3D geologic models of the lobes with triaxial ellipsoids that suitably represent the overall layers arrangement reveals characteristics that are consistent with an impact between two roughly ellipsoidal cometesimals that produced large-scale axial compression and transversal elongation. The observed features imply global transfer of impact-related shortening into transversal strain. These elements delineate a model for the global rheology of cometesimals that could be possible evoking a prominent bonding action of ice and, to a minor extent, organics., Competing Interests: The authors declare no competing interest.
Published: 2020
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37. Acute In Vivo Electrophysiological Recordings of Local Field Potentials and Multi-unit Activity from the Hyperdirect Pathway in Anesthetized Rats.

Author: Haumesser JK, Kühn J, Güttler C, Nguyen DH, Beck MH, Kühn AA, and van Riesen C
Subjects: Animals, Basal Ganglia physiopathology, Electrocorticography, Electrodes, Electrophysiology instrumentation, Male, Motor Cortex physiopathology, Neurosciences instrumentation, Rats, Action Potentials physiology, Brain physiopathology, Electrophysiology methods, Neural Pathways physiology, Neurosciences methods
Abstract: Converging evidence shows that many neuropsychiatric diseases should be understood as disorders of large-scale neuronal networks. To better understand the pathophysiological basis of these diseases, it is necessary to precisely characterize in which way the processing of information is disturbed between the different neuronal parts of the circuit. Using extracellular in vivo electrophysiological recordings, it is possible to accurately delineate neuronal activity within a neuronal network. The application of this method has several advantages over alternative techniques, e.g., functional magnetic resonance imaging and calcium imaging, as it allows a unique temporal and spatial resolution and does not rely on genetically engineered organisms. However, the use of extracellular in vivo recordings is limited since it is an invasive technique that cannot be universally applied. In this article, a simple and easy to use method is presented with which it is possible to simultaneously record extracellular potentials such as local field potentials and multiunit activity at multiple sites of a network. It is detailed how a precise targeting of subcortical nuclei can be achieved using a combination of stereotactic surgery and online analysis of multi-unit recordings. Thus, it is demonstrated, how a complete network such as the hyperdirect cortico-basal ganglia loop can be studied in anesthetized animals in vivo.
Published: 2017
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38. Surface changes on comet 67P/Churyumov-Gerasimenko suggest a more active past.

Author: El-Maarry MR, Groussin O, Thomas N, Pajola M, Auger AT, Davidsson B, Hu X, Hviid SF, Knollenberg J, Güttler C, Tubiana C, Fornasier S, Feller C, Hasselmann P, Vincent JB, Sierks H, Barbieri C, Lamy P, Rodrigo R, Koschny D, Keller HU, Rickman H, A'Hearn MF, Barucci MA, Bertaux JL, Bertini I, Besse S, Bodewits D, Cremonese G, Da Deppo V, Debei S, De Cecco M, Deller J, Deshapriya JD, Fulle M, Gutierrez PJ, Hofmann M, Ip WH, Jorda L, Kovacs G, Kramm JR, Kührt E, Küppers M, Lara LM, Lazzarin M, Lin ZY, Lopez Moreno JJ, Marchi S, Marzari F, Mottola S, Naletto G, Oklay N, Pommerol A, Preusker F, Scholten F, and Shi X
Abstract: The Rosetta spacecraft spent ~2 years orbiting comet 67P/Churyumov-Gerasimenko, most of it at distances that allowed surface characterization and monitoring at submeter scales. From December 2014 to June 2016, numerous localized changes were observed, which we attribute to cometary-specific weathering, erosion, and transient events driven by exposure to sunlight and other processes. While the localized changes suggest compositional or physical heterogeneity, their scale has not resulted in substantial alterations to the comet's landscape. This suggests that most of the major landforms were created early in the comet's current orbital configuration. They may even date from earlier if the comet had a larger volatile inventory, particularly of CO or CO 2 ices, or contained amorphous ice, which could have triggered activity at greater distances from the Sun., (Copyright © 2017, American Association for the Advancement of Science.)
Published: 2017
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39. Rosetta's comet 67P/Churyumov-Gerasimenko sheds its dusty mantle to reveal its icy nature.

Author: Fornasier S, Mottola S, Keller HU, Barucci MA, Davidsson B, Feller C, Deshapriya JD, Sierks H, Barbieri C, Lamy PL, Rodrigo R, Koschny D, Rickman H, A'Hearn M, Agarwal J, Bertaux JL, Bertini I, Besse S, Cremonese G, Da Deppo V, Debei S, De Cecco M, Deller J, El-Maarry MR, Fulle M, Groussin O, Gutierrez PJ, Güttler C, Hofmann M, Hviid SF, Ip WH, Jorda L, Knollenberg J, Kovacs G, Kramm R, Kührt E, Küppers M, Lara ML, Lazzarin M, Moreno JJ, Marzari F, Massironi M, Naletto G, Oklay N, Pajola M, Pommerol A, Preusker F, Scholten F, Shi X, Thomas N, Toth I, Tubiana C, and Vincent JB
Abstract: The Rosetta spacecraft has investigated comet 67P/Churyumov-Gerasimenko from large heliocentric distances to its perihelion passage and beyond. We trace the seasonal and diurnal evolution of the colors of the 67P nucleus, finding changes driven by sublimation and recondensation of water ice. The whole nucleus became relatively bluer near perihelion, as increasing activity removed the surface dust, implying that water ice is widespread underneath the surface. We identified large (1500 square meters) ice-rich patches appearing and then vanishing in about 10 days, indicating small-scale heterogeneities on the nucleus. Thin frosts sublimating in a few minutes are observed close to receding shadows, and rapid variations in color are seen on extended areas close to the terminator. These cyclic processes are widespread and lead to continuously, slightly varying surface properties., (Copyright © 2016, American Association for the Advancement of Science.)
Published: 2016
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40. Two independent and primitive envelopes of the bilobate nucleus of comet 67P.

Author: Massironi M, Simioni E, Marzari F, Cremonese G, Giacomini L, Pajola M, Jorda L, Naletto G, Lowry S, El-Maarry MR, Preusker F, Scholten F, Sierks H, Barbieri C, Lamy P, Rodrigo R, Koschny D, Rickman H, Keller HU, A'Hearn MF, Agarwal J, Auger AT, Barucci MA, Bertaux JL, Bertini I, Besse S, Bodewits D, Capanna C, Da Deppo V, Davidsson B, Debei S, De Cecco M, Ferri F, Fornasier S, Fulle M, Gaskell R, Groussin O, Gutiérrez PJ, Güttler C, Hviid SF, Ip WH, Knollenberg J, Kovacs G, Kramm R, Kührt E, Küppers M, La Forgia F, Lara LM, Lazzarin M, Lin ZY, Lopez Moreno JJ, Magrin S, Michalik H, Mottola S, Oklay N, Pommerol A, Thomas N, Tubiana C, and Vincent JB
Abstract: The factors shaping cometary nuclei are still largely unknown, but could be the result of concurrent effects of evolutionary and primordial processes. The peculiar bilobed shape of comet 67P/Churyumov-Gerasimenko may be the result of the fusion of two objects that were once separate or the result of a localized excavation by outgassing at the interface between the two lobes. Here we report that the comet's major lobe is enveloped by a nearly continuous set of strata, up to 650 metres thick, which are independent of an analogous stratified envelope on the minor lobe. Gravity vectors computed for the two lobes separately are closer to perpendicular to the strata than those calculated for the entire nucleus and adjacent to the neck separating the two lobes. Therefore comet 67P/Churyumov-Gerasimenko is an accreted body of two distinct objects with 'onion-like' stratification, which formed before they merged. We conclude that gentle, low-velocity collisions occurred between two fully formed kilometre-sized cometesimals in the early stages of the Solar System. The notable structural similarities between the two lobes of comet 67P/Churyumov-Gerasimenko indicate that the early-forming cometesimals experienced similar primordial stratified accretion, even though they formed independently.
Published: 2015
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41. COMETARY SCIENCE. The nonmagnetic nucleus of comet 67P/Churyumov-Gerasimenko.

Author: Auster HU, Apathy I, Berghofer G, Fornacon KH, Remizov A, Carr C, Güttler C, Haerendel G, Heinisch P, Hercik D, Hilchenbach M, Kührt E, Magnes W, Motschmann U, Richter I, Russell CT, Przyklenk A, Schwingenschuh K, Sierks H, and Glassmeier KH
Abstract: Knowledge of the magnetization of planetary bodies constrains their origin and evolution, as well as the conditions in the solar nebular at that time. On the basis of magnetic field measurements during the descent and subsequent multiple touchdown of the Rosetta lander Philae on the comet 67P/Churyumov-Gerasimenko (67P), we show that no global magnetic field was detected within the limitations of analysis. The Rosetta Magnetometer and Plasma Monitor (ROMAP) suite of sensors measured an upper magnetic field magnitude of less than 2 nanotesla at the cometary surface at multiple locations, with the upper specific magnetic moment being <3.1 × 10(-5) ampere-square meters per kilogram for meter-size homogeneous magnetized boulders. The maximum dipole moment of 67P is 1.6 × 10(8) ampere-square meters. We conclude that on the meter scale, magnetic alignment in the preplanetary nebula is of minor importance., (Copyright © 2015, American Association for the Advancement of Science.)
Published: 2015
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42. COMETARY SCIENCE. The landing(s) of Philae and inferences about comet surface mechanical properties.

Author: Biele J, Ulamec S, Maibaum M, Roll R, Witte L, Jurado E, Muñoz P, Arnold W, Auster HU, Casas C, Faber C, Fantinati C, Finke F, Fischer HH, Geurts K, Güttler C, Heinisch P, Herique A, Hviid S, Kargl G, Knapmeyer M, Knollenberg J, Kofman W, Kömle N, Kührt E, Lommatsch V, Mottola S, Pardo de Santayana R, Remetean E, Scholten F, Seidensticker KJ, Sierks H, and Spohn T
Abstract: The Philae lander, part of the Rosetta mission to investigate comet 67P/Churyumov-Gerasimenko, was delivered to the cometary surface in November 2014. Here we report the precise circumstances of the multiple landings of Philae, including the bouncing trajectory and rebound parameters, based on engineering data in conjunction with operational instrument data. These data also provide information on the mechanical properties (strength and layering) of the comet surface. The first touchdown site, Agilkia, appears to have a granular soft surface (with a compressive strength of 1 kilopascal) at least ~20 cm thick, possibly on top of a more rigid layer. The final landing site, Abydos, has a hard surface., (Copyright © 2015, American Association for the Advancement of Science.)
Published: 2015
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43. Large heterogeneities in comet 67P as revealed by active pits from sinkhole collapse.

Author: Vincent JB, Bodewits D, Besse S, Sierks H, Barbieri C, Lamy P, Rodrigo R, Koschny D, Rickman H, Keller HU, Agarwal J, A'Hearn MF, Auger AT, Barucci MA, Bertaux JL, Bertini I, Capanna C, Cremonese G, Da Deppo V, Davidsson B, Debei S, De Cecco M, El-Maarry MR, Ferri F, Fornasier S, Fulle M, Gaskell R, Giacomini L, Groussin O, Guilbert-Lepoutre A, Gutierrez-Marques P, Gutiérrez PJ, Güttler C, Hoekzema N, Höfner S, Hviid SF, Ip WH, Jorda L, Knollenberg J, Kovacs G, Kramm R, Kührt E, Küppers M, La Forgia F, Lara LM, Lazzarin M, Lee V, Leyrat C, Lin ZY, Lopez Moreno JJ, Lowry S, Magrin S, Maquet L, Marchi S, Marzari F, Massironi M, Michalik H, Moissl R, Mottola S, Naletto G, Oklay N, Pajola M, Preusker F, Scholten F, Thomas N, Toth I, and Tubiana C
Abstract: Pits have been observed on many cometary nuclei mapped by spacecraft. It has been argued that cometary pits are a signature of endogenic activity, rather than impact craters such as those on planetary and asteroid surfaces. Impact experiments and models cannot reproduce the shapes of most of the observed cometary pits, and the predicted collision rates imply that few of the pits are related to impacts. Alternative mechanisms like explosive activity have been suggested, but the driving process remains unknown. Here we report that pits on comet 67P/Churyumov-Gerasimenko are active, and probably created by a sinkhole process, possibly accompanied by outbursts. We argue that after formation, pits expand slowly in diameter, owing to sublimation-driven retreat of the walls. Therefore, pits characterize how eroded the surface is: a fresh cometary surface will have a ragged structure with many pits, while an evolved surface will look smoother. The size and spatial distribution of pits imply that large heterogeneities exist in the physical, structural or compositional properties of the first few hundred metres below the current nucleus surface.
Published: 2015
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44. Cometary science. The morphological diversity of comet 67P/Churyumov-Gerasimenko.

Author: Thomas N, Sierks H, Barbieri C, Lamy PL, Rodrigo R, Rickman H, Koschny D, Keller HU, Agarwal J, A'Hearn MF, Angrilli F, Auger AT, Barucci MA, Bertaux JL, Bertini I, Besse S, Bodewits D, Cremonese G, Da Deppo V, Davidsson B, De Cecco M, Debei S, El-Maarry MR, Ferri F, Fornasier S, Fulle M, Giacomini L, Groussin O, Gutierrez PJ, Güttler C, Hviid SF, Ip WH, Jorda L, Knollenberg J, Kramm JR, Kührt E, Küppers M, La Forgia F, Lara LM, Lazzarin M, Lopez Moreno JJ, Magrin S, Marchi S, Marzari F, Massironi M, Michalik H, Moissl R, Mottola S, Naletto G, Oklay N, Pajola M, Pommerol A, Preusker F, Sabau L, Scholten F, Snodgrass C, Tubiana C, Vincent JB, and Wenzel KP
Abstract: Images of comet 67P/Churyumov-Gerasimenko acquired by the OSIRIS (Optical, Spectroscopic and Infrared Remote Imaging System) imaging system onboard the European Space Agency's Rosetta spacecraft at scales of better than 0.8 meter per pixel show a wide variety of different structures and textures. The data show the importance of airfall, surface dust transport, mass wasting, and insolation weathering for cometary surface evolution, and they offer some support for subsurface fluidization models and mass loss through the ejection of large chunks of material., (Copyright © 2015, American Association for the Advancement of Science.)
Published: 2015
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45. Cometary science. On the nucleus structure and activity of comet 67P/Churyumov-Gerasimenko.

Author: Sierks H, Barbieri C, Lamy PL, Rodrigo R, Koschny D, Rickman H, Keller HU, Agarwal J, A'Hearn MF, Angrilli F, Auger AT, Barucci MA, Bertaux JL, Bertini I, Besse S, Bodewits D, Capanna C, Cremonese G, Da Deppo V, Davidsson B, Debei S, De Cecco M, Ferri F, Fornasier S, Fulle M, Gaskell R, Giacomini L, Groussin O, Gutierrez-Marques P, Gutiérrez PJ, Güttler C, Hoekzema N, Hviid SF, Ip WH, Jorda L, Knollenberg J, Kovacs G, Kramm JR, Kührt E, Küppers M, La Forgia F, Lara LM, Lazzarin M, Leyrat C, Lopez Moreno JJ, Magrin S, Marchi S, Marzari F, Massironi M, Michalik H, Moissl R, Mottola S, Naletto G, Oklay N, Pajola M, Pertile M, Preusker F, Sabau L, Scholten F, Snodgrass C, Thomas N, Tubiana C, Vincent JB, Wenzel KP, Zaccariotto M, and Pätzold M
Abstract: Images from the OSIRIS scientific imaging system onboard Rosetta show that the nucleus of 67P/Churyumov-Gerasimenko consists of two lobes connected by a short neck. The nucleus has a bulk density less than half that of water. Activity at a distance from the Sun of >3 astronomical units is predominantly from the neck, where jets have been seen consistently. The nucleus rotates about the principal axis of momentum. The surface morphology suggests that the removal of larger volumes of material, possibly via explosive release of subsurface pressure or via creation of overhangs by sublimation, may be a major mass loss process. The shape raises the question of whether the two lobes represent a contact binary formed 4.5 billion years ago, or a single body where a gap has evolved via mass loss., (Copyright © 2015, American Association for the Advancement of Science.)
Published: 2015
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46. Cometary science. Dust measurements in the coma of comet 67P/Churyumov-Gerasimenko inbound to the Sun.

Author: Rotundi A, Sierks H, Della Corte V, Fulle M, Gutierrez PJ, Lara L, Barbieri C, Lamy PL, Rodrigo R, Koschny D, Rickman H, Keller HU, López-Moreno JJ, Accolla M, Agarwal J, A'Hearn MF, Altobelli N, Angrilli F, Barucci MA, Bertaux JL, Bertini I, Bodewits D, Bussoletti E, Colangeli L, Cosi M, Cremonese G, Crifo JF, Da Deppo V, Davidsson B, Debei S, De Cecco M, Esposito F, Ferrari M, Fornasier S, Giovane F, Gustafson B, Green SF, Groussin O, Grün E, Güttler C, Herranz ML, Hviid SF, Ip W, Ivanovski S, Jerónimo JM, Jorda L, Knollenberg J, Kramm R, Kührt E, Küppers M, Lazzarin M, Leese MR, López-Jiménez AC, Lucarelli F, Lowry SC, Marzari F, Epifani EM, McDonnell JA, Mennella V, Michalik H, Molina A, Morales R, Moreno F, Mottola S, Naletto G, Oklay N, Ortiz JL, Palomba E, Palumbo P, Perrin JM, Rodríguez J, Sabau L, Snodgrass C, Sordini R, Thomas N, Tubiana C, Vincent JB, Weissman P, Wenzel KP, Zakharov V, and Zarnecki JC
Abstract: Critical measurements for understanding accretion and the dust/gas ratio in the solar nebula, where planets were forming 4.5 billion years ago, are being obtained by the GIADA (Grain Impact Analyser and Dust Accumulator) experiment on the European Space Agency's Rosetta spacecraft orbiting comet 67P/Churyumov-Gerasimenko. Between 3.6 and 3.4 astronomical units inbound, GIADA and OSIRIS (Optical, Spectroscopic, and Infrared Remote Imaging System) detected 35 outflowing grains of mass 10(-10) to 10(-7) kilograms, and 48 grains of mass 10(-5) to 10(-2) kilograms, respectively. Combined with gas data from the MIRO (Microwave Instrument for the Rosetta Orbiter) and ROSINA (Rosetta Orbiter Spectrometer for Ion and Neutral Analysis) instruments, we find a dust/gas mass ratio of 4 ± 2 averaged over the sunlit nucleus surface. A cloud of larger grains also encircles the nucleus in bound orbits from the previous perihelion. The largest orbiting clumps are meter-sized, confirming the dust/gas ratio of 3 inferred at perihelion from models of dust comae and trails., (Copyright © 2015, American Association for the Advancement of Science.)
Published: 2015
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47. Granular convection and the Brazil nut effect in reduced gravity.

Author: Güttler C, von Borstel I, Schräpler R, and Blum J
Abstract: We present laboratory experiments of a vertically vibrated granular medium consisting of 1-mm-diameter glass beads with embedded 8-mm-diameter intruder glass beads. The experiments were performed in the laboratory as well as in a parabolic flight under reduced-gravity conditions (on Martian and Lunar gravity levels). We measured the mean rise velocity of the large glass beads and present its dependence on the fill height of the sample containers, the excitation acceleration, and the ambient gravity level. We find that the rise velocity scales in the same manner for all three gravity regimes and roughly linearly with gravity.
Published: 2013
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