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1. AI Assisted Data Selection of Laser Altimeter Observations

Author: Oliver Stenzel, Lukas Maes, and Martin Hilchenbach
Abstract: Laser altimeters create large amounts of data that often have to be preprocessed and checked before further use. The BepiColombo mission to Mercury is set to arrive in December 2025 and observations with the BepiColombo Laser Altimeter (BELA, (Benkhoff et al., 2010; Thomas et al., 2021)) will start during the following spring. These measurements are planned to be used to derive information about the tides of Mercury (Thor et al., 2020). Careful assessment, selection, and filtering on the raw data is needed to extract the small tidal signal. Until the BELA data becomes available artificial data and records from other missions have to be used to study the data selection strategy. We present our work on MESSENGER Laser Altimeter (MLA, (Cavanaugh et al., 2007)) using a convolutional neural network to sort observations on an orbit by orbit basis into different classes. The already existing neural network (Stenzel and Hilchenbach, 2021; Stenzel, Thor and Hilchenbach, 2021) is tuned and a new test data set is created. Benkhoff, J. et al. (2010) ‘BepiColombo—Comprehensive exploration of Mercury: Mission overview and science goals’, Planetary and Space Science, 58(1), pp. 2–20. Available at: https://doi.org/10.1016/j.pss.2009.09.020. Cavanaugh, J.F. et al. (2007) ‘The Mercury Laser Altimeter Instrument for the MESSENGER Mission’, Space Science Reviews, 131(1), pp. 451–479. Available at: https://doi.org/10.1007/s11214-007-9273-4. Stenzel, O. and Hilchenbach, M. (2021) ‘Towards machine learning assisted error identification in orbital laser altimetry for tides derivation’, pp. EPSC2021-688. Available at: https://doi.org/10.5194/espc2021-688. Stenzel, O., Thor, R. and Hilchenbach, M. (2021) ‘Error identification in orbital laser altimeter data by machine learning’, pp. EGU21-14749. Available at: https://doi.org/10.5194/egusphere-egu21-14749. Thomas, N. et al. (2021) ‘The BepiColombo Laser Altimeter’, Space Science Reviews, 217(1), p. 25. Available at: https://doi.org/10.1007/s11214-021-00794-y. Thor, R.N. et al. (2020) ‘Prospects for measuring Mercury’s tidal Love number h2 with the BepiColombo Laser Altimeter’, Astronomy & Astrophysics, 633, p. A85. Available at: https://doi.org/10.1051/0004-6361/201936517.
Published: 2023
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2. A space instrument combining NIR hyperspectral microscopy and Laser-CosmOrbitrap mass spectrometry for the in situ analysis of extraterrestrial dust

Author: Christelle Briois, Donia Baklouti, Noémie Comtesse, Cécile Engrand, Jean-Pierre Lebreton, Ricardo Arevalo, Cédric Pilorget, Laurent Thirkell, Fabrice Colin, Oliver Stenzel, Martin Hilchenbach, and Cardon, Catherine
Subjects: [SDU] Sciences of the Universe [physics]
Abstract: Introduction: The Rosetta mission is one of the latest great scientific and technological European successes. The probe and its lander Philae, transported some very audacious and inventive instruments that for some worked beyond expectations, and gave the scientists and engineers involved an expertise and experience that we should try to build on. The COmetary Secondary Ion Mass Analyser (COSIMA) onboard Rosetta, was the first instrument applying in situ analyses of cometary grains [1]. This instrument already combined two techniques: visible microscopy that was crucial to detect routinely the collected dust and characterize its structure [2], and Time-Of-Flight Secondary Ion Mass Spectrometry that mainly allowed us to determine the elemental composition of the dust [3-4]. COSIMA covered a mass range 1–1200 u but was limited to a mass resolution m/Δm of 1400 at mass 100 u at Full Width Half Maximum (FWHM), which made the assignment of molecular signals difficult. For the next generation of extraterrestrial (especially, primitive) dust analyzers, we are proposing an instrument that combines near infrared (NIR) and visible microscopy with laser ionization mass spectrometry (LIMS). This multi-analysis instrument (named dPCA for dust Particle Composition Analyzer) was part of the Castalia+ mission proposition to the ESA M7 call, but it is potentially suited for any space mission aiming to characterize dusty materials, especially complex ones containing organic and mineral phases. In the prospect to build a new generation of mass spectrometer offering High Resolution Mass Spectrometry (HRMS) collaborative effort between consortium of French and Czech laboratories (LPC2E, LATMOS, LISA, IPAG, IJCLab, J. Heyrovsky Institute of Physical Chemistry) and University of Maryland and NASA GSFC, are on-going to settle a pulsed UV laser source with an Orbitrap™ [5] mass analyzer for planetary applications. The spaceflight and ruggedized version of the Orbitrap cell and its electronics (preamplifier, ultra-stable High Voltage), the CosmOrbitrap mass analyzer/detector, is capable of discriminating isobaric interferences with ultrahigh mass resolution m/Δm > 100,000 (FWHM), high mass accuracies and dual polarity measurements [6-10]. The NIR channel of the microscope will be based on the MicrOmega hyperspectral instrument developed at IAS (Orsay, France). Several replicas of this instrument have already flown or are currently working aboard MASCOT/Hayabusa2, on the ExoMars rover [11] and currently in the JAXA curation facility for Ryugu dust analysis [12]). In this study, we investigated the analytical value of combining these two techniques. We will show through laboratory measurements how combining infrared and mass data could be extremely useful to unambiguously characterize the targeted dust. Experimental Procedure: The main well known inputs given by the NIR spectra are: the detection and characterization of hydration signatures, especially on silicates, the detection and partial characterization of carbonates and sulfates, the detection of ammoniated compounds, the detection of the presence of organic compounds and the detection and identification of ices (H2O, CO2, etc.). In the context of main belt comets, asteroids and even the Martian moons and surface, the full characterization of hydration signatures is one of the most important information needed to complete the mass spectra characterization. For this reason, we started our set of experiments and measurements on both instruments, a laboratory MicrOmega replica at IAS, and a laboratory instrument prototype of a laser ablation / ionization Orbitrap™ mass spectrometer, the LAb-CosmOrbitrap, developed at LPC2E (Orléans, France), by focusing on hydrated and anhydrous silicates. The LAb-CosmOrbitrap integrates i) a commercial pulsed Nd-YAG laser used at 266 nm UV wavelength, ii) a set of ion focusing lenses without C-trap, and iii) a spaceflight CosmOrbitrap mass analyzer/detector. Variable output energy of laser beam can be operated thanks to a polarizing prism. Samples: To explore the capabilities of the LAb-CosmOrbitrap instrument to characterize silicate in both positive and negative ion mode, we started with analyses of a San Carlos olivine, and a natural Mg-rich serpentine dominated by antigorite and chrysotile. Both samples are obviously silicates, but the former is an anhydrous ionic solid (no covalent bond between O and Mg) and the latter is a phyllosilicate (= a hydrated silicate) where Mg is covalently bonded to O and OH. Same samples have been analyzed with MicrOmega replica instrument. Results: LAb-CosmOrbitrap measurements in positive ion modes of the serpentine sample enables detection of various oxide and hydroxide magnesium peaks at high mass accuracy (< 2.5 ppm) during a single laser shot experiment, with high mass resolution (for examples m/∆m ~ 160,000 (FWHM) for 24MgOH+ and m/∆m > 130,000 (FWHM) for 24Mg2O+). In this study, we explored the best suitable laser energy and consecutive shot sequences to find reproducible and robust measurements of oxide and hydroxide ions. These results will be presented among those on olivine and the spectra obtained with NIR microscopy. Conclusions: This study demonstrates the capabilities of a UV Laser-CosmOrbitrap instrument combined with a NIR spectrometer to detect and characterize hydrated signatures of a serpentine with an optimized protocol. Next steps that will be pursued are among others the analyses of other types of silicates and minerals, of silicate doped with organic compounds. In the prospect of a future space instrument, it is obvious that IR microscopy would be of great benefit for a fast screening of the area of the targeted dust in order to further perform LIMS analyses and increase the confidence in the identification of molecular and structural indices. Acknowledgement: We thank the Centre National des Etudes Spatiales (CNES) for their financial support. References: [1] Hilchenbach et al. (2016) ApJL 816, L32. [2] Langevin et al. (2016) Icarus 271, 76–97. [3] Fray et al. (2016) Nature 538, 72–74. [4] Bardyn, Baklouti et al. (2017) MNRAS 469, S712–S722. [5] Makarov (1999) US Patent 5, 886, 346. [6] Briois et al. (2016) PSS 131, 33–45. [7] Arevalo Jr. et al. (2018) Rapid Comm 32, 1875–1886. [8] Selliez et al. (2019) PSS 170, 42–51. [9] Selliez et al. (2020) Rapid Comm 34, e8645. [10] Cherville et al. (2021) COSPAR2021, Abstract B0.4-0018-21. [11] Pilorget and Bibring (2014) PSS 99, 7–18. [12] Pilorget et al. (2021) Nature Astronomy 6, 221–225.
Published: 2022
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3. The Structure of the Global Heliosphere as Seen by In-Situ Ions from the Voyagers and Remotely Sensed ENAs from Cassini

Author: Konstantinos Dialynas, Stamatios M. Krimigis, Robert B. Decker, Matthew Hill, Donald G. Mitchell, Ke Chiang Hsieh, Martin Hilchenbach, and Andrzej Czechowski
Subjects: Space and Planetary Science, Astronomy and Astrophysics
Abstract: The exploration of interplanetary space and our solar bubble, the heliosphere, has made a big leap over the past two decades, due to the path-breaking observations of the two Voyager spacecraft, launched more than 44 years ago. Their in-situ particle and fields measurements were complemented by remote observations of 5.2 to 55 keV Energetic Neutral Atoms (ENA) from the Cassini mission (Ion and Neutral Camera-INCA), revealing a number of previously unanticipated heliospheric structures such as the “Belt”, a region of enhanced particle pressure inside the heliosheath. The Suprathermal Time Of Flight (HSTOF) instrument on the Solar and Heliospheric Observatory (SOHO) also provided information of 58–88 keV ENAs from the heliosphere. In this chapter we provide a brief discussion for the contribution of the Voyager 1 and 2 Low Energy Charged Particle (LECP) observations that provided “ground truth” to the ENA images from Cassini/INCA towards addressing fundamental questions for the heliosphere’s interaction with the Very Local Interstellar Medium.
Published: 2022
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4. D/H in the refractory organics of comet 67P/Churyumov-Gerasimenko measured by Rosetta /COSIMA

Author: John Paquette, Jouni Rynö, Oliver Stenzel, A. Bardyn, Cécile Engrand, Martin Hilchenbach, Henning Fischer, Sandra Siljeström, Nicolas Fray, C. M. O'd. Alexander, Jochen Kissel, H. Cottin, Sihane Merouane, R. Isnard, Laboratoire de Physique des 2 Infinis Irène Joliot-Curie (IJCLab), and Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, 010504 meteorology & atmospheric sciences, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], 0103 physical sciences, Comet, Astronomy and Astrophysics, 010303 astronomy & astrophysics, 01 natural sciences, Refractory (planetary science), 0105 earth and related environmental sciences, Astrobiology
Abstract: The D/H ratio is a clue to the origin and evolution of hydrogen-bearing chemical species in Solar system materials. D/H has been observed in the coma of many comets, but most such measurements have been for gaseous water. We present the first in situ measurements of the D/H ratios in the organic refractory component of cometary dust particles collected at very low impact speeds in the coma of comet 67P/Churyumov-Gerasimenko (hereafter 67P) by the COSIMA instrument onboard Rosetta. The values measured by COSIMA are spatial averages over an approximately 35 × 50 µm2 area. The average D/H ratio for the 25 measured particles is (1.57 ± 0.54) × 10−3, about an order of magnitude higher than the Vienna Standard Mean Ocean Water (VSMOW), but more than an order of magnitude lower than the values measured in gas-phase organics in solar-like protostellar regions and hot cores. This relatively high averaged value suggests that refractory carbonaceous matter in comet 67P is less processed than the most primitive insoluble organic matter (IOM) in meteorites, which has a D/H ratio in the range of about 1 to 7 × 10−4. The cometary particles measured in situ also have a higher H/C ratio than the IOM. We deduce that the measured D/H in cometary refractory organics is an inheritance from the presolar molecular cloud from which the Solar system formed. The high D/H ratios observed in the cometary particles challenges models in which high D/H ratios result solely from processes that operated in the protosolar disc.
Published: 2021
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5. A cosmic dust detection suite for the deep space Gateway

Author: Martin Hilchenbach, R. Srama, P.J. Wozniakiewicz, Mark J. Burchell, F. Postberg, Harald Krüger, Jon K. Hillier, Veerle Sterken, Sihane Merouane, M. van-Ginneken, Mario Trieloff, John Bridges, V. Della Corte, William Carey, James Carpenter, A.T. Kearsley, A. Dignam, Ernesto Palomba, J. Schmidt, M.J. Genge, and L. J. Hicks
Subjects: Atmospheric Science, 010504 meteorology & atmospheric sciences, Aerospace Engineering, Flux, NASA Deep Space Network, Lunar orbit, 01 natural sciences, 7. Clean energy, Astrobiology, 0103 physical sciences, Cosmic dust, Moon, Impacts, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Earth's orbit, Gateway (telecommunications), Payload, Astronomy and Astrophysics, Debris, Geophysics, 13. Climate action, Space and Planetary Science, Physics::Space Physics, General Earth and Planetary Sciences, Environmental science, Astrophysics::Earth and Planetary Astrophysics, QB651
Abstract: The decade of the 2020s promises to be when humanity returns to space beyond Earth orbit, with several nations trying to place astronauts on the Moon, before going further into deep space. As part of such a programme, NASA and partner organisations, propose to build a Deep Space Gateway in lunar orbit by the mid-2020s. This would be visited regularly and offer a platform for science as well as for human activity. Payloads that can be mounted externally on the Gateway offer the chance to, amongst other scientific goals, monitor and observe the dust flux in the vicinity of the Moon. This paper looks at relevant technologies to measure dust which will impact the exposed surface at high speed. Flux estimates and a model payload of detectors are described. It is predicted that the flux is sufficient to permit studies of cometary vs. asteroidal dust and their composition, and to sample interstellar dust streams. This may also be the last opportunity to measure the natural dust flux near the Moon before the current, relatively pristine environment, is contaminated by debris, as humanity’s interest in the Moon generates increased activity in that vicinity in coming decades. ISSN:0273-1177 ISSN:1879-1948
Published: 2021

6. Do twin spectral peaks of olivine particles in the thermal infrared diagnose their sizes and porosities?

Author: Hiroshi Kimura, Johannes Markkanen, Ludmilla Kolokolova, Martin Hilchenbach, Koji Wada, Yasumasa Kanada, and Takafumi Matsui
Subjects: Earth and Planetary Astrophysics (astro-ph.EP), Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Astrophysics - Instrumentation and Methods for Astrophysics, Astrophysics - Astrophysics of Galaxies, Instrumentation and Methods for Astrophysics (astro-ph.IM), Astrophysics - Earth and Planetary Astrophysics, Physics::Geophysics
Abstract: A well-established constraint on the size of non-porous olivine grains or the porosity of aggregates consisting of small olivine grains from prominent narrow peaks in thermal infrared spectra characteristic of crystalline silicates is reexamined. To thoroughly investigate thermal infrared peaks, we make theoretical argument for the absorption and scattering of light by non-porous, non-spherical olivine particles, which is followed by numerical verification. Our study provides perfectly rational explanations of the physics behind the small-particle effect of emission peaks in the framework of classical electrodynamics and convincing evidence of small-particle's emission peaks in the literature. While resonant absorption excited by surface roughness on the order of submicrometer scales can be identified even for non-porous olivine particles with a radius of $10~{\rm \mu m}$, it makes only a negligible contribution to thermal infrared spectra of the particles. In contrast, the porosity of non-spherical particles has a significant impact on the strength and wavelength of the peaks, while the resonant absorption excited by an ensemble of small grains takes place at a wavelength different than one expects for surface roughness. We finally reaffirm that twin peaks of olivine in thermal infrared spectra of dust particles in astronomical environments are the intrinsic diagnostic characters of submicrometer-sized small grains and their aggregate particles in fluffy and porous configurations., Comment: 16 pages, 8 figures, to appear in Icarus
Published: 2022
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7. The BepiColombo Mercury Imaging X-Ray Spectrometer: Science goals, instrument performance and operations

Author: Oliver Blake, Jens Ormö, Raymond Fairbend, Tatsuaki Okada, HR Williams, Arto V. Luttinen, Juhani Huovelin, Petra Majewski, Emma J. Bunce, Martin Hilchenbach, Tuomo Tikkanen, Adrian Martindale, G. P. Hall, Katherine H. Joy, Corinne Barcelo-Garcia, Miguel Mas-Hesse, C. Feldman, Nathalie Vaudon, Jose Viceira-Martín, Ulrich R. Christensen, Ian A. Crawford, Chris Bicknell, Lothar Strüder, Andy Cheney, Suzanne M. Imber, Phil A. Bland, Maria Genzer, Tony Crawford, Timo Väisänen, Steve Milan, John Bridges, S. Nenonen, Nigel Bannister, Christopher Thomas, Arto Lehtolainen, Ana Balado Margeli, Rosie Hodnett, Esa Kallio, Jim Pearson, Konrad Dennerl, D. Ross, Emile Schyns, Simon Lindsay, Eero Esko, Paul Drumm, Miriam Pajas-Sanz, Eddy Robert, S. Korpela, Tomas Kohout, Ivor Mcdonnell, Maria Luisa Lara, Johannes Treis, Guilhem Alibert, Richard Poyner, Mahesh Anand, Manuel Grande, Maria Angeles Alcacera-Gil, Peter Millington-Hotze, Karri Muinonen, D. Willingale, Paul Houghton, Michele K. Dougherty, Larry R. Nittler, Antti Penttilä, Gillian Butcher, J. Thornhill, David A. Rothery, Sylvestre Maurice, Tim K. Yeoman, Julien Seguy, Juan Pérez-Mercader, European Space Agency, Science and Technology Facilities Council (UK), UK Space Agency, Ministerio de Economía y Competitividad (España), Ministerio de Ciencia e Innovación (España), European Commission, Academy of Finland, University of Leicester, University of Helsinki, Open University Milton Keynes, Semiconductor Laboratory of the Max Planck Society, PNSensor GmbH, Max Planck Institute for Solar System Research, University of Manchester, Instituto Nacional de Tecnica Aeroespacial, Photonis, Curtin University, Birkbeck University of London, Max Planck Institute for Extraterrestrial Physics, Imperial College London, Finnish Meteorological Institute, Aberystwyth University, Esa Kallio Group, CSIC, Oxford Instruments Analytical Oy, Carnegie Institution of Washington, JAXA Institute of Space and Astronautical Science, Harvard University, Department of Electronics and Nanoengineering, Aalto-yliopisto, and Aalto University
Subjects: 010504 meteorology & atmospheric sciences, BepiColombo, chemistry.chemical_element, 7. Clean energy, 01 natural sciences, Collimated light, law.invention, Telescope, Optics, law, Planet, 0103 physical sciences, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, X-ray spectrometry, Spectrometer, business.industry, Astronomy and Astrophysics, Mercury, Charged particle, Mercury (element), X-ray emission, Planetary science, es, chemistry, 13. Climate action, Space and Planetary Science, Surface composition, Elemental composition, Environmental science, Astrophysics::Earth and Planetary Astrophysics, business, Space environment
Abstract: Full list of authors: Bunce, Emma J.; Martindale, Adrian; Lindsay, Simon; Muinonen, Karri; Rothery, David A.; Pearson, Jim; McDonnell, Ivor; Thomas, Chris; Thornhill, Julian; Tikkanen, Tuomo; Feldman, Charly; Huovelin, Juhani; Korpela, Seppo; Esko, Eero; Lehtolainen, Arto; Treis, Johannes; Majewski, Petra; Hilchenbach, Martin; Väisänen, Timo; Luttinen, Arto; Kohout, Tomas; Penttilä, Antti; Bridges, John; Joy, Katherine H.; Alcacera-Gil, Maria Angeles; Alibert, Guilhem; Anand, Mahesh; Bannister, Nigel; Barcelo-Garcia, Corinne; Bicknell, Chris; Blake, Oliver; Bland, Phil; Butcher, Gillian; Cheney, Andy; Christensen, Ulrich; Crawford, Tony; Crawford, Ian A.; Dennerl, Konrad; Dougherty, Michele; Drumm, Paul; Fairbend, Raymond; Genzer, Maria; Grande, Manuel; Hall, Graeme P.; Hodnett, Rosie; Houghton, Paul; Imber, Suzanne; Kallio, Esa; Lara, Maria Luisa; Balado Margeli, Ana; Mas-Hesse, Miguel J.; Maurice, Sylvestre; Milan, Steve; Millington-Hotze, Peter; Nenonen, Seppo; Nittler, Larry; Okada, Tatsuaki; Ormö, Jens; Perez-Mercader, Juan; Poyner, Richard; Robert, Eddy; Ross, Duncan; Pajas-Sanz, Miriam; Schyns, Emile; Seguy, Julien; Strüder, Lothar; Vaudon, Nathalie; Viceira-Martín, Jose; Williams, Hugo; Willingale, Dick; Yeoman, Tim.-- This is an open access article., The Mercury Imaging X-ray Spectrometer is a highly novel instrument that is designed to map Mercury’s elemental composition from orbit at two angular resolutions. By observing the fluorescence X-rays generated when solar-coronal X-rays and charged particles interact with the surface regolith, MIXS will be able to measure the atomic composition of the upper ∼10-20 μm of Mercury’s surface on the day-side. Through precipitating particles on the night-side, MIXS will also determine the dynamic interaction of the planet’s surface with the surrounding space environment. MIXS is composed of two complementary elements: MIXS-C is a collimated instrument which will achieve global coverage at a similar spatial resolution to that achieved (in the northern hemisphere only – i.e. ∼ 50 – 100 km) by MESSENGER; MIXS-T is the first ever X-ray telescope to be sent to another planet and will, during periods of high solar activity (or intense precipitation of charged particles), reveal the X-ray flux from Mercury at better than 10 km resolution. The design, performance, scientific goals and operations plans of the instrument are discussed, including the initial results from commissioning in space. © 2020, The Author(s)., The MIXS team has gratefully received funding from a consortium of agencies across Europe. The UK Space Agency are the lead funding agency, supported by national contributions from our amazing panEuropean team and the European Space Agency. UK funding has come from, the science and technology facilities council - STFC (grant numbers: PP/E002056/1; PP/E002412/1; ST/L000776/1; ST/M002101/1; ST/M002187/1; ST/N00339X/1; ST/N000471/1; ST/P001963/1; ST/S002596/1; ST/J000213/1), the United Kingdom Space Agency -UKSA (grant numbers: ST/P000908/1; ST/T001542/1; ST/K003194/1; ST/L000318/1; ST/M000702/1) and the European Space Agency -ESA (contract numbers: 4000118221/16/ES/JD; RES-PSS/NR/035-B/200; 20919/07/NF/FG). Images shown in Fig. 4, Fig. 6 and Fig. 9 are adapted from drawings produced by MagnaParva Ltd. under ESA contract number 20919/07/NL/FG. EJB is supported by a Royal Society Wolfson Research Merit Award. The DEPFET X-ray detectors were contributed with the support of dedicated Max Planck Society grants by MPG and MPS as well as ESA contract number 4000108312. The Spanish contribution was funded by MEC/MINECO/MICINN grants; AYA200803467/ESP, AYA2011-24780, AYA2012-39362-C02-01, ESP2014-59789-P and ESP2015-65712-C5-1-R. Finnish hardware contributions were funded by Tekes (now "Business Finland") during the era from 2004 to 2019. Research at the University of Helsinki is supported, in part, by the Academy of Finland (grant number 1325805).
Published: 2020

8. Dust-to-Gas and Refractory-to-Ice Mass Ratios of Comet 67P/Churyumov-Gerasimenko from Rosetta Observations

Author: Ekkehard Kührt, Nicolas Biver, Dominique Bockelée-Morvan, Raphael Marschall, Mathieu Choukroun, Matthew Taylor, Nicolas Thomas, Kathrin Altwegg, Martin Hilchenbach, Martin Pätzold, Alain Herique, Joanna Drążkowska, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Physikalisches Institut [Bern], Universität Bern [Bern], DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), 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'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)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP), Ludwig Maximilian University of Munich [Germany] (LMU München), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Rhenish Institute for Environmental Research (RIU), University of Cologne, RSSD of ESA, ESTEC, Noordwijk, The Netherlands, and Physics Institute, University of Bern, 3012 Bern, Switzerland
Subjects: Physics, 67P/Churyumov-Gerasimenko, 010504 meteorology & atmospheric sciences, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], 520 Astronomy, refractory-to-ice ratio, Comet, Astronomy and Astrophysics, Astrophysics, Mass ratio, 620 Engineering, 01 natural sciences, Planetary science, Space and Planetary Science, [SDU]Sciences of the Universe [physics], 0103 physical sciences, Rosetta, Comets, Refractory-to-Ice mass ratio, Single point, Dust-to-gas ratio, 010303 astronomy & astrophysics, Institut für Optische Sensorsysteme, Refractory (planetary science), 0105 earth and related environmental sciences
Abstract: This chapter reviews the estimates of the dust-to-gas and refractory-to-ice mass ratios derived fromRosettameasurements in the lost materials and the nucleus of 67P/Churyumov-Gerasimenko, respectively. First, the measurements byRosettainstruments are described, as well as relevant characteristics of 67P. The complex picture of the activity of 67P, with its extreme North-South seasonal asymmetry, is presented. Individual estimates of the dust-to-gas and refractory-to-ice mass ratios are then presented and compared, showing wide ranges of plausible values.Rosetta’s wealth of information suggests that estimates of the dust-to-gas mass ratio made in cometary comae at a single point in time may not be fully representative of the refractory-to-ice mass ratio within the cometary nuclei being observed.
Published: 2020
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9. Reconstruction of the flight and attitude of Rosetta's lander Philae

Author: Christoph Statz, Philip Heinisch, Martin Hilchenbach, Ronny Hahnel, Felix Finke, Holger Sierks, Dirk Plettemeier, Wlodek Kofman, Karl-Heinz Glassmeier, Yves Rogez, Hans-Ulrich Auster, Eric Jurado, Romain Garmier, Carsten Güttler, Thierry Martin, Ingo Richter, and Alain Herique
Subjects: 010504 meteorology & atmospheric sciences, Comet, Aerospace Engineering, Touchdown, Geodesy, Collision, 01 natural sciences, law.invention, Data link, Orbiter, Radio tracking, law, 0103 physical sciences, Trajectory, Descent (aeronautics), 010303 astronomy & astrophysics, Geology, 0105 earth and related environmental sciences
Abstract: Since Rosetta's lander Philae touched down on comet 67P/Churyumov-Gerasimenko on November 12, 2014, many tools have been applied to reconstruct Philae's flight path and attitude between separation, the touchdowns, collision and the final landing at Abydos. In addition to images from the cameras onboard both orbiter and lander (“OSIRIS”, “CIVA” and “ROLIS”), radio tracking results, solar array and radio data link housekeeping data, one of the major sources for timing and attitude information were two point magnetic field measurements by the magnetometers “ROMAP” and “RPC-MAG” aboard Philae and Rosetta. In this study all the different results are combined to determine in further detail what happened to Philae during its travel above the surface of 67P/Churyumov-Gerasimenko. In addition to a description of the descent dynamics and the attitude during rebound, the approximate coordinates for the collision at 16:20 UTC with the rim of the Hatmehit crater and the second touchdown are estimated. It is also shown, that Philae did not change attitude between the end of the first-science sequence and September 2, 2016.
Published: 2017
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10. Evidence of sub-surface energy storage in comet 67P from the outburst of 2016 July 03

Author: M. A. Barucci, Eberhard Grün, Giampiero Naletto, Ivano Bertini, M. De Cecco, Pedro Hasselmann, S. Mottola, Wing-Huen Ip, Laurent Jorda, Bernhard Geiger, Xian Shi, Maurizio Pajola, Jouni Rynö, Gabriele Cremonese, Oliver Stenzel, J. J. Lopez Moreno, J. L. Bertaux, J. Kissel, S. Höfner, M. F. A'Hearn, Olivier Groussin, Martin Hilchenbach, B. Zaprudin, Steve Boudreault, V. Da Deppo, Alessandra Rotundi, Ludmilla Kolokolova, Dennis Bodewits, Philippe Lamy, Jessica Agarwal, Marc Hofmann, Paul D. Feldman, Horst Uwe Keller, Stefano Debei, Sihane Merouane, J. Wm. Parker, Monica Lazzarin, Stubbe F. Hviid, Michael Küppers, Stavro Ivanovski, Cesare Barbieri, Jean-Baptiste Vincent, Francesco Marzari, Detlef Koschny, Yves Langevin, Sonia Fornasier, N. Oklay, L. M. Lara, Jakob Deller, Zhong-Yi Lin, A. Koch, Andrew J. Steffl, R. Rodrigo, Björn Davidsson, J.-R. Kramm, Carsten Güttler, E. Kührt, Cecilia Tubiana, Klaus Hornung, P. J. Gutierrez, Stephen C. Lowry, Jörg Knollenberg, Holger Sierks, Henning Fischer, Marco Fulle, V. Della Corte, A. Gicquel, Harold A. Weaver, Nicolas Thomas, Lori M. Feaga, Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Dipartimento di Scienze e Tecnologie [Napoli] (DIST), Università degli Studi di Napoli 'Parthenope' = University of Naples (PARTHENOPE), Department of Physics and Astronomy [Baltimore], Johns Hopkins University (JHU), European Space Astronomy Centre (ESAC), Agence Spatiale Européenne = European Space Agency (ESA), Centro di Ateneo di Studi e Attività Spaziali 'Giuseppe Colombo' (CISAS), Università degli Studi di Padova = University of Padua (Unipd), 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), Max-Planck-Institut für Kernphysik (MPIK), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], Istituto di Astrofisica Spaziale e Fisica cosmica - Roma (IASF-Roma), Istituto Nazionale di Astrofisica (INAF), NASA Ames Research Center (ARC), Department of Space Studies [Boulder], Southwest Research Institute [Boulder] (SwRI), Physikalisches Institut [Bern], Universität Bern [Bern] (UNIBE), Dipartimento di Fisica e Astronomia 'Galileo Galilei', PLANETO - 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), INAF - Osservatorio Astronomico di Padova (OAPD), 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], 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), Universität der Bundeswehr München [Neubiberg], DLR Institut für Planetenforschung, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), 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], von Hoerner und Sulger GmbH, European Space Research and Technology Centre (ESTEC), Research and Scientific Support Department, ESTEC (RSSD), Agence Spatiale Européenne = European Space Agency (ESA)-Agence Spatiale Européenne = European Space Agency (ESA), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Centre for Astrophysics and Planetary Science [Canterbury] (CAPS), University of Kent [Canterbury], CNR Istituto di Fotonica e Nanotecnologie [Padova] (IFN), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), International Space Science Institute [Bern] (ISSI), Finnish Meteorological Institute (FMI), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Tuorla Observatory, University of Turku, Lowry, S.C., ITA, FRA, DEU, ESP, Centre National de la Recherche Scientifique (France), German Centre for Air and Space Travel, Agenzia Spaziale Italiana, Swedish National Space Board, Ministerio de Economía y Competitividad (España), European Space Agency, Max-Planck-Institut für Sonnensystemforschung (MPS), Universita degli studi di Napoli 'Parthenope' [Napoli], European Space Agency (ESA), Universita degli Studi di Padova, Universität Bern [Bern], 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), Consiglio Nazionale delle Ricerche [Roma] (CNR), California Institute of Technology (CALTECH)-NASA, European Space Agency (ESA)-European Space Agency (ESA), and Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)
Subjects: Asteroiden und Kometen, Solid state: refractory, Acceleration of particles, 010504 meteorology & atmospheric sciences, 01 natural sciences, law.invention, Astrobiology, Scattering, individual: 67P/Churyumov-Gerasimenko [Comets], law, Rosetta, 0103 physical sciences, Surface change, Astrophysics::Solar and Stellar Astrophysics, Sunrise, OSIRIS, Solid state: volatile, Crystallization, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Comets: individual: 67P/Churyumov-Gerasimenko, [PHYS]Physics [physics], Physics, ta115, 520 Astronomy, volatile [Solid state], general [Comets], Astronomy and Astrophysics, Solar illumination, 620 Engineering, Surface energy, Amorphous solid, Comets: general, On board, 13. Climate action, Space and Planetary Science, acceleration of particles, scattering, solid state: refractory, solid state: volatile, comets: general, comets: individual: 67P/Churyumov-Gerasimenko, Physics::Space Physics, Sublimation (phase transition), QB651, Astrophysics::Earth and Planetary Astrophysics, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], refractory [Solid state]
Abstract: On 2016 July 03, several instruments onboard ESA's Rosetta spacecraft detected signs of an outburst event on comet 67P, at a heliocentric distance of 3.32 au from the Sun, outbound from perihelion. We here report on the inferred properties of the ejected dust and the surface change at the site of the outburst. The activity coincided with the local sunrise and continued over a time interval of 14-68 min. It left a 10-m-sized icy patch on the surface. The ejected material comprised refractory grains of several hundred microns in size, and sub-micron-sized water ice grains. The high dust mass production rate is incompatible with the free sublimation of crystalline water ice under solar illumination as the only acceleration process. Additional energy stored near the surface must have increased the gas density. We suggest a pressurized sub-surface gas reservoir, or the crystallization of amorphous water ice as possible causes.© 2015 The Authors., The support of the national funding agencies of Germany (DLR, grant 50 QP 1302), France (CNES), Austria, Finland and the ESA Technical Directorate is gratefully acknowledged.
Published: 2017
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11. The footprint of cometary dust analogues. - I

Author: H. John, Bastian Gundlach, Carsten Dominik, A. Landeck, Mark Bentley, L. E. Ellerbroek, Sihane Merouane, H. A. van Veen, Thurid Mannel, Martin Hilchenbach, Jürgen Blum, Low Energy Astrophysics (API, FNWI), and Medical Biology
Subjects: Physics, Earth and Planetary Astrophysics (astro-ph.EP), 010504 meteorology & atmospheric sciences, Spacecraft, business.industry, Comet, Interplanetary medium, FOS: Physical sciences, Astronomy and Astrophysics, Coma (optics), Astrophysics, Collision, 01 natural sciences, Astrobiology, Ion, Footprint, 13. Climate action, Space and Planetary Science, Planet, 0103 physical sciences, Astrophysics::Earth and Planetary Astrophysics, business, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Astrophysics - Earth and Planetary Astrophysics
Abstract: Cometary dust provides a unique window on dust growth mechanisms during the onset of planet formation. Measurements by the Rosetta spacecraft show that the dust in the coma of comet 67P/Churyumov-Gerasimenko has a granular structure at size scales from sub-um up to several hundreds of um, indicating hierarchical growth took place across these size scales. However, these dust particles may have been modified during their collection by the spacecraft instruments. Here we present the results of laboratory experiments that simulate the impact of dust on the collection surfaces of COSIMA and MIDAS, instruments onboard the Rosetta spacecraft. We map the size and structure of the footprints left by the dust particles as a function of their initial size (up to several hundred um) and velocity (up to 6 m/s). We find that in most collisions, only part of the dust particle is left on the target; velocity is the main driver of the appearance of these deposits. A boundary between sticking/bouncing and fragmentation as an outcome of the particle-target collision is found at v ~ 2 m/s. For velocities below this value, particles either stick and leave a single deposit on the target plate, or bounce, leaving a shallow footprint of monomers. At velocities > 2 m/s and sizes > 80 um, particles fragment upon collision, transferring up to 50 per cent of their mass in a rubble-pile-like deposit on the target plate. The amount of mass transferred increases with the impact velocity. The morphologies of the deposits are qualitatively similar to those found by the COSIMA instrument., 14 pages, 12 figures, accepted for publication in MNRAS
Published: 2017
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12. Evolution of the physical properties of dust and cometary dust activity from 67P/Churyumov–Gerasimenko measured in situ by Rosetta/COSIMA

Author: Klaus Hornung, Rita Schulz, J. Kissel, B. Zaprudin, Martin Hilchenbach, Jouni Rynö, Henning Fischer, Sihane Merouane, Yves Langevin, Eva Maria Mellado, Nicolas Altobelli, and Oliver Stenzel
Subjects: In situ, Physics, 010504 meteorology & atmospheric sciences, Space and Planetary Science, 0103 physical sciences, Astronomy, Astronomy and Astrophysics, 010303 astronomy & astrophysics, 01 natural sciences, 0105 earth and related environmental sciences, Astrobiology
Published: 2017
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13. Composition of cometary particles collected during two periods of the Rosetta mission: multivariate evaluation of mass spectral data

Author: Martin Hilchenbach, Jochen Kissel, A. Bardyn, Sandra Siljeström, Kurt Varmuza, John Paquette, Oliver Stenzel, Nicolas Fray, Johan Silen, Hervé Cottin, Sihane Merouane, Christelle Briois, Donia Baklouti, Peter Filzmoser, Vienna University of Technology (TU Wien), Institute of Statistics and Mathematical Methods in Economics, Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Laboratoire de Physiogénomique / NeuroTranscriptomes et Paléogénétique (LPG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Geophysical Laboratory of the Carnegie Institution, Carnegie Institution for Science, Finnish Meteorological Institute Observation Services, Finnish Meteorological Institute (FMI), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Sonnensystemforschung (MPS), Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Road, Washington DC 20015, USA, Technische Universität Wien (TU Wien), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES)
Subjects: Multivariate statistics, Dust particles, Comet, KNN classification, Special Issue ‐ Research Articles, 02 engineering and technology, 01 natural sciences, Analytical Chemistry, Astrobiology, random forest classification, 020401 chemical engineering, time-offlight secondary ion mass spectrometry, Mass analyzer, 0204 chemical engineering, Spectral data, Applied Mathematics, 010401 analytical chemistry, Special Issue ‐ Research Article, comet 67P/Churyumov-Gerasimenko, 0104 chemical sciences, 13. Climate action, [SDU]Sciences of the Universe [physics], variable importance, Environmental science, time‐of‐flight secondary ion mass spectrometry, comet 67P/Churyumov‐Gerasimenko
Abstract: The instrument COSIMA (COmetary Secondary Ion Mass Analyzer) onboard of the European Space Agency mission Rosetta collected and analyzed dust particles in the neighborhood of comet 67P/Churyumov‐Gerasimenko. The chemical composition of the particle surfaces was characterized by time‐of‐flight secondary ion mass spectrometry. A set of 2213 spectra has been selected, and relative abundances for CH‐containing positive ions as well as positive elemental ions define a set of multivariate data with nine variables. Evaluation by complementary chemometric techniques shows different compositions of sample groups collected during two periods of the mission. The first period was August to November 2014 (far from the Sun); the second period was January 2015 to February 2016 (nearer to the Sun). The applied data evaluation methods consider the compositional nature of the mass spectral data and comprise robust principal component analysis as well as classification with discriminant partial least squares regression, k‐nearest neighbor search, and random forest decision trees. The results indicate a high importance of the relative abundances of the secondary ions C+ and Fe+ for the group separation and demonstrate an enhanced content of carbon‐containing substances in samples collected in the period with smaller distances to the Sun., Extraterrestrial dust particles from the neighborhood of comet 67P/Churyumov‐Gerasimenko have been collected by the instrument COSIMA onboard of the European Space Agency mission Rosetta. The composition of the particles was characterized by time‐of‐flight secondary ion mass spectrometry giving evidence of minerals and macromolecular organic substances. A specific multivariate evaluation of the mass spectral data by chemometric methods indicates an enhanced content of carbon‐containing substances in samples collected in a period with smaller distances to the Sun.
Published: 2020
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14. Optical properties of cometary particles collected by COSIMA: Assessing the differences between microscopic and macroscopic scales

Author: Sihane Merouane, Martin Hilchenbach, Rita Schulz, Jouni Rynö, Klaus Hornung, Mathieu Vincendon, Cecile Engrand, Jochen Kissel, Yves Langevin, Institut d'astrophysique spatiale (IAS), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
Subjects: Physics, Range (particle radiation), 010504 meteorology & atmospheric sciences, biology, Comet, Phase (waves), [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Astronomy and Astrophysics, Scale (descriptive set theory), Astrophysics, biology.organism_classification, 01 natural sciences, Reflectivity, Lower half, Wavelength, Space and Planetary Science, 0103 physical sciences, Osiris, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: International audience; The COSIMA mass spectrometer on-board Rosetta was equipped with an optical microscope, Cosiscope, which identified several 10,000 cometary particles collected on targets exposed during the orbital phase around the nucleus of comet 67P Churyumov-Gerasimenko. The median value of reflectance factors evaluated from Cosiscope images for large collected particles (~10.5% (Langevin et al., 2017), lies above the range of reflectance observed by the OSIRIS camera at a similar wavelength (5-7%, (Fornasier et al., 2015), but at much larger scales (a few 10 cm instead of a few 10 μm). In order to better understand this discrepancy, the assumptions underlying the derivation of reflectance factors have been reassessed using laboratory measurements of COSIMA targets and analogs of cometary particles. The approach of Langevin et al. is validated, but we consider that the uncertainty on reflectance factors was conservative. The reflectance factors are likely to lie in the lower half of the previously estimated range, which reduces (but does not eliminate) the discrepancy with OSIRIS albedos. The remaining discrepancy can be attributed primarily to the difference in scale (factor 10,000 in pixel size between COSIMA and OSIRIS)
Published: 2019
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15. Heliospheric structure as revealed by the 3 -- 88 keV H ENA spectra

Author: Marzena A. Kubiak, Nikolai V. Pogorelov, Martin Hilchenbach, Maciej Bzowski, J. M. Sokół, Nathan A. Schwadron, A. Czechowski, Jacob Heerikhuisen, Eric J. Zirnstein, J. Grygorczuk, and Gary P. Zank
Subjects: Physics, Range (particle radiation), 010504 meteorology & atmospheric sciences, Energetic neutral atom, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Astronomy and Astrophysics, Astrophysics, Solar physics, 01 natural sciences, Spectral line, Space Physics (physics.space-ph), Pickup Ion, Solar wind, Astrophysics - Solar and Stellar Astrophysics, Physics - Space Physics, Space and Planetary Science, Observatory, 0103 physical sciences, Physics::Space Physics, 010303 astronomy & astrophysics, Heliosphere, Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences
Abstract: Energetic neutral atoms (ENA) are an important tool for investigating the structure of the heliosphere. Recently, it was observed that fluxes of ENAs (with energy $\le$ 55 keV) coming from the upwind and downwind regions of the heliosphere are similar in strength. This led the authors of these observations to hypothesize that the heliosphere is bubble-like rather than comet-like, meaning that it has no extended tail. We investigate the directional distribution of the ENA flux for a wide energy range (3--88 keV) including the observations from IBEX (Interstellar Boundary Explorer), INCA (Ion and Neutral Camera, on board Cassini), and HSTOF (High energy Suprathermal Time Of Flight sensor, on board SOHO, Solar and Heliospheric Observatory). An essential element is the model of pickup ion acceleration at the termination shock (TS) proposed by Zank. We use state of the art models of the global heliosphere, interstellar neutral gas density, and pickup ion distributions. The results, based on the "comet-like" model of the heliosphere, are close in flux magnitude to ENA observations by IBEX, HSTOF and partly by INCA (except for the 5.2-13.5 keV energy channel). We find that the ENA flux from the tail dominates at high energy (in agreement with HSTOF, but not INCA). At low energy, our comet-like model produces the similar strengths of the ENA fluxes from the upwind and downwind directions, which, therefore, removes this as a compelling argument for a bubble-like heliosphere., Accepted for publication in The Astrophysical Journal
Published: 2019

16. H/C elemental ratio of the refractory organic matter in cometary particles of 67P/Churyumov-Gerasimenko

Author: C. Briois, Martin Hilchenbach, Nicolas Fray, Hervé Cottin, Kurt Varmuza, Donia Baklouti, Sandra Siljeström, Conel M. O'd. Alexander, A. Bardyn, John Paquette, François-Régis Orthous-Daunay, Cecile Engrand, Oliver Stenzel, Robin Isnard, Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Institut national des sciences de l'Univers (INSU - CNRS), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Carnegie Institution for Science [Washington], Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), 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), RISE Research Institutes of Sweden, Institute of Statistics and Mathematical Methods in Economics, ANR: 10-LABX-0047,ESEP,Space explorations of Planetary Environments(2010), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), 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]), ANR-10-LABX-0047,ESEP,Space explorations of Planetary Environments(2010), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), and Carnegie Institution for Science
Subjects: Physics, chemistry.chemical_classification, Astrochemistry, 010504 meteorology & atmospheric sciences, Comet, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Astronomy and Astrophysics, Context (language use), Astrophysics, 01 natural sciences, Secondary ion mass spectrometry, Meteorite, chemistry, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], 0103 physical sciences, Atomic ratio, Organic matter, comets: individual: 67P/Churyumov-Gerasimenko / astrochemistry, 010303 astronomy & astrophysics, Refractory (planetary science), 0105 earth and related environmental sciences
Abstract: Context. Because comets are part of the most primitive bodies of our solar system, establishing their chemical composition and comparing them to other astrophysical bodies gives new constraints on the formation and evolution of organic matter throughout the solar system. For two years, the time-of-flight secondary ion mass spectrometer COmetary Secondary Ion Mass Analyzer (COSIMA) on board the Rosetta orbiter performed in situ analyses of the dust particles ejected from comet 67P/Churyumov-Gerasimenko (67P). Aims. The aim is to determine the H/C elemental ratio of the refractory organic component contained in cometary particles of 67P. Methods. We analyzed terrestrial and extraterrestrial calibration samples using the COSIMA ground-reference model. Exploiting these calibration samples, we provide calibration lines in both positive and negative ion registration modes. Thus, we are now able to measure the cometary H/C elemental ratio. Results. The mean H/C value is 1.04 ± 0.16 based on 33 different cometary particles. Consequently, the H/C atomic ratio is on average higher in cometary particles of 67P than in even the most primitive insoluble organic matter extracted from meteorites. Conclusions. These results imply that the refractory organic matter detected in dust particles of 67P is less unsaturated than the material in meteorites.
Published: 2019
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17. The footprint of cometary dust analogues: II. Morphology as a tracer of tensile strength and application to dust collection by the Rosetta spacecraft

Author: Carsten Dominik, Jürgen Blum, Bastian Gundlach, A. Landeck, H. John, Martin Hilchenbach, H. A. van Veen, L. E. Ellerbroek, Sihane Merouane, Medical Biology, and Low Energy Astrophysics (API, FNWI)
Subjects: Physics, Earth and Planetary Astrophysics (astro-ph.EP), Planetesimal, 010504 meteorology & atmospheric sciences, Instrumentation, Extinction (astronomy), Comet, Mineralogy, Interplanetary medium, FOS: Physical sciences, Astronomy and Astrophysics, 01 natural sciences, Strength of materials, 13. Climate action, Space and Planetary Science, Mass transfer, 0103 physical sciences, Ultimate tensile strength, Astrophysics - Instrumentation and Methods for Astrophysics, 010303 astronomy & astrophysics, Instrumentation and Methods for Astrophysics (astro-ph.IM), Astrophysics - Earth and Planetary Astrophysics, 0105 earth and related environmental sciences
Abstract: The structure of cometary dust is a tracer of growth processes in the formation of planetesimals. Instrumentation on board the Rosetta mission to comet 67P/Churyumov- Gerasimenko captured dust particles and analysed them in situ. However, these deposits are a product of a collision within the instrument. We conducted laboratory experiments with cometary dust analogues, simulating the collection process by Rosetta instruments (specifically COSIMA, MIDAS). In Paper I we reported that velocity is a key driver in determining the appearance of deposits. Here in Paper II we use materials with different monomer sizes, and study the effect of tensile strength on the appearance of deposits. We find that mass transfer efficiency increases from $\sim$1 up to $\sim$10% with increasing monomer diameter from 0.3 $\mu$m to 1.5 $\mu$m (i.e. tensile strength decreasing from $\sim$12 to $\sim$3 kPa), and velocities increasing from 0.5 to 6 m/s. Also, the relative abundance of small fragments after impact is higher for material with higher tensile strength. The degeneracy between the effects of velocity and material strength may be lifted by performing a closer study of the deposits. This experimental method makes it possible to estimate the mass transfer efficiency in the COSIMA instrument. Extrapolating these results implies that more than half of the dust collected during the Rosetta mission has not been imaged. We analysed two COSIMA targets containing deposits from single collisions. The collision that occurred closest to perihelion passage led to more small fragments on the target., Comment: 13 pages, 11 figures, accepted for publication in MNRAS
Published: 2019
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18. 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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19. The Morphological, Elastic, and Electric Properties of Dust Aggregates in Comets: A Close Look at COSIMA/Rosetta's Data on Dust in Comet 67P/Churyumov-Gerasimenko

Author: Oliver Stenzel, Hiroshi Kimura, John Paquette, Sihane Merouane, and Martin Hilchenbach
Subjects: Solar System, 010504 meteorology & atmospheric sciences, Infrared, Comet, FOS: Physical sciences, Astrophysics::Cosmology and Extragalactic Astrophysics, 01 natural sciences, Astrobiology, law.invention, Orbiter, law, 0103 physical sciences, Astrophysics::Solar and Stellar Astrophysics, 010303 astronomy & astrophysics, Astrophysics::Galaxy Astrophysics, 0105 earth and related environmental sciences, Earth and Planetary Astrophysics (astro-ph.EP), Meteoroid, Astronomy and Astrophysics, Rainout, Meteorite, Space and Planetary Science, Physics::Space Physics, Astrophysics::Earth and Planetary Astrophysics, Formation and evolution of the Solar System, Astrophysics - Earth and Planetary Astrophysics
Abstract: The Cometary Secondary Ion Mass Analyzer (COSIMA) onboard ESA's Rosetta orbiter has revealed that dust particles in the coma of Comet 67P/Churyumov-Gerasimenko are aggregates of small grains. We study the morphological, elastic, and electric properties of dust aggregates in the coma of Comet 67P/Churyumov-Gerasimenko using optical microscopic images taken by the COSIMA instrument. Dust aggregates in COSIMA images are well represented as fractals in harmony with morphological data from MIDAS (Micro-Imaging Dust Analysis System) and GIADA (Grain Impact Analyzer and Dust Accumulator) onboard Rosetta. COSIMA's images, together with the data from the other Rosetta's instruments such as MIDAS and GIADA do not contradict the so-called rainout growth of $10~\mu\mathrm{m}$-sized particles in the solar nebula. The elastic and electric properties of dust aggregates measured by COSIMA suggest that the surface chemistry of cometary dust is well represented as carbonaceous matter rather than silicates or ices, consistent with the mass spectra, and that organic matter is to some extent carbonized by solar radiation, as inferred from optical and infrared observations of various comets. Electrostatic lofting of cometary dust by intense electric fields at the terminator of its parent comet is unlikely, unless the surface chemistry of the dust changes from a dielectric to a conductor. Our findings are not in conflict with our current understanding of comet formation and evolution, which begin with the accumulation of condensates in the solar nebula and follow with the formation of a dust mantle in the inner solar system., Comment: 17 pages, 12 figures, 1 tables, to appear in Planetary and Space Science
Published: 2019
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20. Electrical properties of cometary dust particles derived from line shapes of TOF-SIMS spectra measured by the ROSETTA/COSIMA instrument

Author: Klaus Hornung, Hervé Cottin, John Paquette, Paola Modica, Harry Lehto, Kurt Varmuza, Rita Schulz, Oliver Stenzel, Martin Hilchenbach, Christelle Briois, Nicolas Fray, Yves Langevin, Laurent Thirkell, Donia Baklouti, Sihane Merouane, Jouni Rynö, Anais Bardyn, Sandra Siljeström, Henning Fischer, Cécile Engrand, Johan Silen, Eva Maria Mellado, Jochen Kissel, Andreas Koch, Institut für Strömungsmechanik und Aerodynamik (LRT-7), Universität der Bundeswehr München [Neubiberg] = Bundeswehr University, Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Climate and Environmental Physics [Bern] (CEP), Physikalisches Institut [Bern], Universität Bern [Bern]-Universität Bern [Bern], Laboratoire de Physiogénomique / NeuroTranscriptomes et Paléogénétique (LPG), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Finnish Meteorological Institute Observation Services, Finnish Meteorological Institute (FMI), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Road, Washington DC 20015, USA, Tuorla Observatory, University of Turku, Technische Universität Wien (TU Wien), University of Salzburg, Universität der Bundeswehr München [Neubiberg], Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Carnegie Institution for Science [Washington], Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), ESA Scientific Support Office, RISE Research Institutes of Sweden, Vienna University of Technology (TU Wien), Carnegie Institution for Science, Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, and PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES)
Subjects: Permittivity, Secondary ion mass spectrometry, Materials science, 010504 meteorology & atmospheric sciences, Electric properties, Comet, Analytical chemistry, 67p/churyumov-gerasimenko, Electrical permittivity, 7. Clean energy, 01 natural sciences, Spectral line, Specific resistivities, Negative ions, Ion, Time of flight, Electrical resistivity and conductivity, 0103 physical sciences, Naturvetenskap, Rosetta mission, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Line (formation), Cometary dust, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Sample charging, Astronomy and Astrophysics, Dust, Time-of-flight mass spectra, Secondary ion mass spectrometers, [PHYS.PHYS.PHYS-SPACE-PH]Physics [physics]/Physics [physics]/Space Physics [physics.space-ph], Cometary dusts, 13. Climate action, Space and Planetary Science, [SDU]Sciences of the Universe [physics], Mass spectrum, Electrical properties, Cometary dust Rosetta mission Electrical properties Time-of-flight mass spectra Sample charging, Natural Sciences, Mass spectrometers
Abstract: Between Aug. 2014 and Sept. 2016, while ESA's cornerstone mission Rosetta was operating in the vicinity of the nucleus and in the coma of comet 67P/Churyumov-Gerasimenko, the COSIMA instrument collected a large number of dust particles with diameters up to a millimeter. Positive or negative ions were detected by a time-of-flight secondary ion mass spectrometer (TOF-SIMS) and the composition of selected particles was deduced. Many of the negative ion mass spectra show, besides mass peaks at the correct position, an additional, extended contribution at the lower mass side caused by partial charging of the dust. This effect, usually avoided in SIMS applications, can in our case be used to obtain information on the electrical properties of the collected cometary dust particles, such as the specific resistivity (ρr>1.2⋅1010Ωm) and the real part of the relative electrical permittivity (εr0.8). Funding details: Austrian Science Fund, FWF, P26871-N20; Funding details: Centre National d’Etudes Spatiales, CNES; Funding details: Deutsches Zentrum für Luft- und Raumfahrt, DLR, 50 QP 1801; Funding text 1: COSIMA was built by a consortium led by the Max-Planck-Institut für Extraterrestrische Physik, Garching, Germany in collaboration with Laboratoire de Physique et Chimie de l’Environnement et de l’Espace, Orléans, France, Institut d’Astrophysique Spatiale, CNRS/Université Paris Sud, Orsay, France, Finnish Meteorological Institute, Helsinki, Finland, Universität Wuppertal, Wuppertal, Germany, von Hoerner und Sulger GmbH, Schwetzingen, Germany, Universität der Bundeswehr München, Neubiberg, Germany, Institut für Physik, Forschungszentrum Seibersdorf, Seibersdorf, Austria, Institut für Weltraumforschung, Österreichische Akademie der Wissenschaften, Graz, Austria and is lead by the Max-Planck-Institut für Sonnensystemforschung, Göttingen, Germany. The support of the national funding agencies of Germany ( DLR , grant 50 QP 1801 ), France ( CNES ), Austria ( FWF , grant P26871-N20 ), Finland 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. Appendix A
Published: 2019
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21. Analysis of COSIMA spectra: Bayesian approach

Author: B. Zaprudin, Johan Silen, Martin Hilchenbach, Harald Krüger, Jochen Kissel, Kirsi Lehto, Jouni Rynö, H. J. Lehto, and Tuomas Lönnberg
Subjects: Atmospheric Science, 010504 meteorology & atmospheric sciences, Chemistry, Bayesian probability, lcsh:QC801-809, Geology, Inverse problem, Dead time, Oceanography, 01 natural sciences, Spectral line, Secondary ion mass spectrometry, lcsh:Geophysics. Cosmic physics, Joint probability distribution, Statistics, Line (geometry), 0103 physical sciences, Mass spectrum, Statistical physics, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: We describe the use of Bayesian analysis methods applied to time-of-flight secondary ion mass spectrometer (TOF-SIMS) spectra. The method is applied to the COmetary Secondary Ion Mass Analyzer (COSIMA) TOF-SIMS mass spectra where the analysis can be broken into subgroups of lines close to integer mass values. The effects of the instrumental dead time are discussed in a new way. The method finds the joint probability density functions of measured line parameters (number of lines, and their widths, peak amplitudes, integrated amplitudes and positions). In the case of two or more lines, these distributions can take complex forms. The derived line parameters can be used to further calibrate the mass scaling of TOF-SIMS and to feed the results into other analysis methods such as multivariate analyses of spectra. We intend to use the method, first as a comprehensive tool to perform quantitative analysis of spectra, and second as a fast tool for studying interesting targets for obtaining additional TOF-SIMS measurements of the sample, a property unique to COSIMA. Finally, we point out that the Bayesian method can be thought of as a means to solve inverse problems but with forward calculations, only with no iterative corrections or other manipulation of the observed data.
Published: 2018

22. Isotopic Composition of the Solar Wind Inferred from In-Situ Spacecraft Measurements

Author: Martin Hilchenbach, K. Bamert, and Reinald Kallenbach
Subjects: Solar System, Nebula, Spectrometer, Spacecraft, business.industry, 530 Physics, Astrophysics::High Energy Astrophysical Phenomena, Astronomy and Astrophysics, Natural abundance, Astrobiology, Solar wind, Planetary science, Space and Planetary Science, Physics::Space Physics, Terrestrial planet, Environmental science, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, business, Nuclear Experiment, Astrophysics::Galaxy Astrophysics
Abstract: The Sun is the largest reservoir of matter in the solar system, which formed 4.6 Gyr ago from the protosolar nebula. Data from space missions and theoretical models indicate that the solar wind carries a nearly unfractionated sample of heavy isotopes at energies of about 1 keV/amu from the Sun into interplanetary space. In anticipation of results from the Genesis mission’s solar-wind implanted samples, we revisit solar wind isotopic abundance data from the high-resolution CELIAS/MTOF spectrometer on board SOHO. In particular, we evaluate the isotopic abundance ratios 15N/14N, 17O/16O, and 18O/16O in the solar wind, which are reference values for isotopic fractionation processes during the formation of terrestrial planets as well as for the Galactic chemical evolution. We also give isotopic abundance ratios for He, Ne, Ar, Mg, Si, Ca, and Fe measured in situ in the solar wind.
Published: 2018
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23. The asteroid-comet continuum from laboratory and space analyses of comet samples and micrometeorites

Author: Martin Hilchenbach, Jean Duprat, John P. Bradley, Cecile Engrand, N. Bardin, Emmanuel Dartois, Karim Benzerara, L. Delauche, E. Dobrica, Laurent Remusat, Eric Quirico, Hugues Leroux, and Hope A. Ishii
Subjects: Physics, Solar System, 010504 meteorology & atmospheric sciences, Comet, Astronomy, Astronomy and Astrophysics, 010502 geochemistry & geophysics, 01 natural sciences, Astrobiology, Interplanetary dust cloud, Meteorite, Space and Planetary Science, Chondrite, Asteroid, Formation and evolution of the Solar System, 0105 earth and related environmental sciences, Cosmic dust
Abstract: Comets are probably the best archives of the nascent solar system, 4.5 Gyr ago, and their compositions reveal crucial clues on the structure and dynamics of the early protoplanetary disk. Anhydrous minerals (olivine and pyroxene) have been identified in cometary dust for a few decades. Surprisingly, samples from comet Wild2 returned by the Stardust mission in 2006 also contain high temperature mineral assemblages like chondrules and refractory inclusions, which are typical components of primitive meteorites (carbonaceous chondrites - CCs). A few Stardust samples have also preserved some organic matter of comet Wild 2 that share some similarities with CCs. Interplanetary dust falling on Earth originate from comets and asteroids in proportions to be further constrained. These cosmic dust particles mostly show similarities with CCs, which in turn only represent a few percent of meteorites recovered on Earth. At least two (rare) families of cosmic dust particles have shown strong evidences for a cometary origin: the chondritic porous interplanetary dust particles (CP-IDPs) collected in the terrestrial stratosphere by NASA, and the ultracarbonaceous Antarctic Micrometeorites (UCAMMs) collected from polar snow and ice by French and Japanese teams. Analyses of dust particles from the Jupiter family comet 67P/Churyumov-Gerasimenko by the dust analyzers on Rosetta orbiter (COSIMA, GIADA, MIDAS) suggest a relationship to interplanetary dust/micrometeorites. A growing number of evidences highlights the existence of a continuum between asteroids and comets, already in the early history of the solar system.
Published: 2015
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24. COSIMA data analysis using multivariate techniques

Author: Harry Lehto, Kurt Varmuza, Sandra Siljeström, Martin Hilchenbach, Hervé Cottin, Jochen Kissel, and Johan Silen
Subjects: Atmospheric Science, Multivariate statistics, Multivariate analysis, 010504 meteorology & atmospheric sciences, Chemistry, Calibration (statistics), business.industry, lcsh:QC801-809, Geology, Pattern recognition, Oceanography, computer.software_genre, 01 natural sciences, Secondary ion mass spectrometry, lcsh:Geophysics. Cosmic physics, Similarity (network science), 0103 physical sciences, Mass spectrum, Data mining, Artificial intelligence, Cluster analysis, business, 010303 astronomy & astrophysics, computer, 0105 earth and related environmental sciences
Abstract: We describe how to use multivariate analysis of complex TOF-SIMS (time-of-flight secondary ion mass spectrometry) spectra by introducing the method of random projections. The technique allows us to do full clustering and classification of the measured mass spectra. In this paper we use the tool for classification purposes. The presentation describes calibration experiments of 19 minerals on Ag and Au substrates using positive mode ion spectra. The discrimination between individual minerals gives a cross-validation Cohen κ for classification of typically about 80%. We intend to use the method as a fast tool to deduce a qualitative similarity of measurements.
Published: 2015
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25. Compressive strength of comet 67P/Churyumov-Gerasimenko derived from Philae surface contacts

Author: Martin Hilchenbach, Bastian Gundlach, Jürgen Blum, Philip Heinisch, Holger Sierks, Ingo Richter, Carsten Güttler, Jens Biele, H. U. Auster, Karl-Heinz Glassmeier, and Cecilia Tubiana
Subjects: Physics, 010504 meteorology & atmospheric sciences, Spacecraft, business.industry, Magnetometer, Comet, Touchdown, Astronomy and Astrophysics, Context (language use), Astrophysics, Trajectory of a projectile, 01 natural sciences, law.invention, Compressive strength, Space and Planetary Science, law, 0103 physical sciences, Trajectory, Aerospace engineering, business, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: Context. The landing and rebound of the Philae lander, which was part of the ESA Rosetta mission, enabled us to study the mechanical properties of the surface of comet 67P/Churyumov-Gerasimenko, because we could use Philae as an impact probe. Aims. The aim is to approximate the descent and rebound trajectory of the Philae lander and use this information to derive the compressive strength of the surface material from the different surface contacts and scratches created during the final touchdown. Combined with laboratory measurements, this can give an insight into what comets are made of and how they formed. Methods. We combined observations from the ROMAP magnetometer on board Philae with observations made by the Rosetta spacecraft, particularly by the OSIRIS camera system and the RPC-MAG magnetometer. Additionally, ballistic trajectory and collision modeling was performed. These results are placed in context using laboratory measurements of the compressibility of different materials. Results. It was possible to reconstruct possible trajectories of Philae and determine that a pressure of ~100 Pa is enough to compress the surface material up to a depth of ~20 cm. Considering all errors, the derived compressive strength shows little dependence on location, with an overall upper limit for the surface compressive strength of ~800 Pa.
Published: 2019
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26. Mechanical and electrostatic experiments with dust particles collected in the inner coma of comet 67P by COSIMA onboard Rosetta

Author: Jochen Kissel, Anais Bardyn, Christelle Briois, Donia Baklouti, Martin Hilchenbach, Kurt Varmuza, Rita Schulz, John Paquette, W. Steiger, Nicolas Altobelli, Nicolas Fray, Sandra Siljeström, Andreas Koch, R. Thomas, Paola Modica, Johan Silen, Klaus Hornung, Henning Fischer, Oliver Stenzel, Yves Langevin, B. Zaprudin, Eva Maria Mellado, Léna Le Roy, Laurent Thirkell, H. Höfner, H. Henkel, Gerhard Haerendel, Hervé Cottin, Jouni Rynö, Sihane Merouane, Cécile Engrand, Harry Lehto, Klaus Torkar, Institut d'astrophysique spatiale ( IAS ), Université Paris-Sud - Paris 11 ( UP11 ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace ( LPC2E ), Centre National de la Recherche Scientifique ( CNRS ) -Université d'Orléans ( UO ) -Institut national des sciences de l'Univers ( INSU - CNRS ), Laboratoire inter-universitaire des systèmes atmosphèriques ( LISA ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Université Paris Diderot - Paris 7 ( UPD7 ) -Université Paris-Est Créteil Val-de-Marne - Paris 12 ( UPEC UP12 ) -Centre National de la Recherche Scientifique ( CNRS ), Centre de Sciences Nucléaires et de Sciences de la Matière ( CSNSM ), Université Paris-Sud - Paris 11 ( UP11 ) -Institut National de Physique Nucléaire et de Physique des Particules du CNRS ( IN2P3 ) -Centre National de la Recherche Scientifique ( CNRS ), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), and Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Institut national des sciences de l'Univers (INSU - CNRS)
Subjects: Physics, ta115, 010504 meteorology & atmospheric sciences, Ion beam, General Mathematics, [ PHYS.ASTR ] Physics [physics]/Astrophysics [astro-ph], Dust particles, General Engineering, General Physics and Astronomy, Astrophysics, 01 natural sciences, Astrobiology, Ion, Secondary ion mass spectrometry, Low speed, 13. Climate action, Agglomerate, [SDU]Sciences of the Universe [physics], Comet nucleus, 0103 physical sciences, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: The in situ cometary dust particle instrument COSIMA (COmetary Secondary Ion Mass Analyser) onboard ESA's Rosetta mission has collected about 31 000 dust particles in the inner coma of comet 67P/Churyumov–Gerasimenko since August 2014. The particles are identified by optical microscope imaging and analysed by time-of-flight secondary ion mass spectrometry. After dust particle collection by low speed impact on metal targets, the collected particle morphology points towards four families of cometary dust particles. COSIMA is an in situ laboratory that operates remotely controlled next to the comet nucleus. The particles can be further manipulated within the instrument by mechanical and electrostatic means after their collection by impact. The particles are stored above 0°C in the instrument and the experiments are carried out on the refractory, ice-free matter of the captured cometary dust particles. An interesting particle morphology class, the compact particles, is not fragmented on impact. One of these particles was mechanically pressed and thereby crushed into large fragments. The particles are good electrical insulators and transform into rubble pile agglomerates by the application of an energetic indium ion beam during the secondary ion mass spectrometry analysis. This article is part of the themed issue ‘Cometary science after Rosetta’.
Published: 2017
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27. Halogens as tracers of protosolar nebula material in comet 67P/Churyumov-Gerasimenko

Author: Martin Hilchenbach, Johan De Keyser, Peter Wurz, Myrtha Hässig, Henri Rème, Stephen A. Fuselier, Jean-Jacques Berthelier, Nicolas Fray, Tamas I. Gombosi, Sébastien Gasc, Frederik Dhooghe, Martin Rubin, Léna Le Roy, Urs Mall, Michael R. Combi, Thierry Sémon, Romain Maggiolo, Bernard Marty, Andrew Gibbons, Kathrin Altwegg, Chia-Yu Tzou, Herbert Gunell, Eddy Equeter, Björn Fiethe, Christelle Briois, Hans Balsiger, Gaël Cessateur, Ursina Calmonte, Eddy Neefs, Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), Centre for Mathematical Plasma-Astrophysics [Leuven] (CmPA), Catholic University of Leuven - Katholieke Universiteit Leuven (KU Leuven), Physikalisches Institut [Bern], Universität Bern [Bern], Center for Space and Habitability (CSH), University of Bern, Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), 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), Department of Climate and Space Sciences and Engineering (CLaSP), University of Michigan [Ann Arbor], University of Michigan System-University of Michigan System, Institute of Computer and Network Engineering [Braunschweig] (IDA), Technische Universität Braunschweig = Technical University of Braunschweig [Braunschweig], Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Space Science and Engineering Division [San Antonio], Southwest Research Institute [San Antonio] (SwRI), The University of Texas at San Antonio (UTSA), Spectroscopie de l'atmosphère, Service de Chimie Quantique et Photophysique, Université libre de Bruxelles (ULB), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] (AOSS), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Centre de Recherches Pétrographiques et Géochimiques (CRPG), Université de Lorraine (UL)-Institut national des sciences de l'Univers (INSU - CNRS)-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), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique ( BIRA-IASB ), Centre for Mathematical Plasma-Astrophysics [Leuven] ( CmPA ), Katholieke Universiteit Leuven ( KU Leuven ), Center for Space and Habitability ( CSH ), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace ( LPC2E ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Université d'Orléans ( UO ) -Centre National de la Recherche Scientifique ( CNRS ), IMPEC - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales ( LATMOS ), Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ) -Université de Versailles Saint-Quentin-en-Yvelines ( UVSQ ) -Université Pierre et Marie Curie - Paris 6 ( UPMC ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), Department of Climate and Space Sciences and Engineering ( CLaSP ), Institute of Computer and Network Engineering [Braunschweig] ( IDA ), Technische Universität Braunschweig [Braunschweig], Laboratoire inter-universitaire des systèmes atmosphèriques ( LISA ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Université Paris Diderot - Paris 7 ( UPD7 ) -Université Paris-Est Créteil Val-de-Marne - Paris 12 ( UPEC UP12 ) -Centre National de la Recherche Scientifique ( CNRS ), Southwest Research Institute [San Antonio] ( SwRI ), The University of Texas at San Antonio ( UTSA ), Université Libre de Bruxelles [Bruxelles] ( ULB ), Department of Atmospheric, Oceanic, and Space Sciences [Ann Arbor] ( AOSS ), Max-Planck-Institut für Sonnensystemforschung ( MPS ), Centre de Recherches Pétrographiques et Géochimiques ( CRPG ), Université de Lorraine ( UL ) -Centre National de la Recherche Scientifique ( CNRS ), Institut de recherche en astrophysique et planétologie ( IRAP ), Université Paul Sabatier - Toulouse 3 ( UPS ) -Observatoire Midi-Pyrénées ( OMP ) -Centre National de la Recherche Scientifique ( CNRS ), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Universität Bern [Bern] (UNIBE), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), 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 Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-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), PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Libre de Bruxelles [Bruxelles] (ULB), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), and Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)
Subjects: Solar System, 010504 meteorology & atmospheric sciences, Hydrogen, 530 Physics, Comet, Analytical chemistry, [SDU.ASTR.EP]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], Halide, chemistry.chemical_element, 01 natural sciences, Astrobiology, 0103 physical sciences, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Nebula, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], 520 Astronomy, Molecular cloud, Astronomy and Astrophysics, 620 Engineering, [ SDU.ASTR.EP ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Earth and Planetary Astrophysics [astro-ph.EP], chemistry, 13. Climate action, Space and Planetary Science, Halogen, Mass spectrum, [ SDU.ASTR.SR ] Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR]
Abstract: International audience; We report the first in situ detection of halogens in a cometary coma, that of 67P/Churyumov-Gerasimenko. Neutral gas mass spectra collected by the European Space Agencys Rosetta spacecraft during four periods of interest from the first comet encounter up to perihelion indicate that the main halogen-bearing compounds are HF, HCl and HBr. The bulk elemental abundances relative to oxygen are ∼8.9 × 10−5 for F/O, ∼1.2 × 10−4 for Cl/O, and ∼2.5 × 10−6 for Br/O, for the volatile fraction of the comet. The cometary isotopic ratios for 37Cl/35Cl and 81Br/79Br match the solar system values within the error margins. The observations point to an origin of the hydrogen halides in molecular cloud chemistry, with frozen hydrogen halides on dust grains, and a subsequent incorporation into comets as the cloud condensed and the solar system formed.
Published: 2017
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28. Nitrogen-to-carbon atomic ratio measured by COSIMA in the particles of comet 67P/Churyumov–Gerasimenko

Author: Christelle Briois, Rita Schulz, Sandra Siljeström, B. Zaprudin, John Paquette, Paola Modica, Jouni Rynö, Henning Fischer, Martin Hilchenbach, Anais Bardyn, Oliver Stenzel, François-Régis Orthous-Daunay, Harry Lehto, Johan Silen, Cécile Engrand, Laurent Thirkell, Robin Isnard, Kurt Varmuza, Eva Maria Mellado, Yves Langevin, Donia Baklouti, Klaus Hornung, Léna Le Roy, Hervé Cottin, Sihane Merouane, J. Kissel, Nicolas Fray, Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Paris (UP)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Laboratoire Imagerie et Systèmes d'Acquisition (LISA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), University of Turku, Universität Bern [Bern], Universität der Bundeswehr München [Neubiberg], 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]), Finnish Meteorological Institute (FMI), RISE Research Institutes of Sweden, Vienna University of Technology (TU Wien), ANR-10-LABX-0047,ESEP,Space explorations of Planetary Environments(2010), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Universität Bern [Bern] (UNIBE), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), and Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS)
Subjects: Astrochemistry, Comet, Analytical chemistry, 010502 geochemistry & geophysics, 01 natural sciences, meteorites, Interplanetary dust cloud, Chondrite, 0103 physical sciences, meteors, meteoroids, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Gerasimenko, Physics, Range (particle radiation), ta115, Meteoroid, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], astrochemistry, comets: general, Astronomy and Astrophysics, Meteorite, 13. Climate action, Space and Planetary Science, comets: individual: 67P/Churyumov, space vehicles, Atomic ratio
Abstract: International audience; The COmetary Secondary Ion Mass Analyzer (COSIMA) on board the Rosetta mission has analysed numerous cometary dust particles collected at very low velocities (a few m s(-1)) in the environment of comet 67P/Churyumov-Gerasimenko (hereafter 67P). In these particles, carbon and nitrogen are expected mainly to be part of the organic matter. We have measured the nitrogen-to-carbon (N/C) atomic ratio of 27 cometary particles. It ranges from 0.018 to 0.06 with an averaged value of 0.035 +/- 0.011. This is compatible with the measurements of the particles of comet 1P/Halley and is in the lower range of the values measured in comet 81P/Wild 2 particles brought back to Earth by the Stardust mission. Moreover, the averaged value found in 67P particles is also similar to the one found in the insoluble organic matter extracted from CM, CI and CR carbonaceous chondrites and to the bulk values measured in most interplanetary dust particles and micrometeorites. The close agreement of the N/C atomic ratio in all these objects indicates that their organic matters share some similarities and could have a similar chemical origin. Furthermore, compared to the abundances of all the detected elements in the particles of 67P and to the elemental solar abundances, the nitrogen is depleted in the particles and the nucleus of 67P as was previously inferred also for comet 1P/Halley. This nitrogen depletion could constrain the formation scenarios of cometary nuclei.
Published: 2017
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29. Carbon-rich dust in comet 67P/Churyumov-Gerasimenko measured by COSIMA/Rosetta

Author: Martin Hilchenbach, Donia Baklouti, John Paquette, Anais Bardyn, Hervé Cottin, Rita Schulz, J. Kissel, Klaus Hornung, Laurent Thirkell, B. Zaprudin, Jouni Rynö, Cécile Engrand, Nicolas Fray, Henning Fischer, François-Régis Orthous-Daunay, Harry Lehto, Sihane Merouane, Kurt Varmuza, Johan Silen, Robin Isnard, Léna Le Roy, N. Ligier, Christelle Briois, Yves Langevin, Paola Modica, Oliver Stenzel, Laboratoire Imagerie et Systèmes d'Acquisition (LISA), Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Centre National de la Recherche Scientifique (CNRS)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Sud - Paris 11 (UP11), Universität der Bundeswehr München [Neubiberg], Université Paris-Est (UPE), Tuorla Observatory, University of Turku, Center for Space and Habitability (CSH), University of Bern, 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]), Finnish Meteorological Institute Observation Services, Finnish Meteorological Institute (FMI), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Vienna University of Technology (TU Wien), ANR-10-LABX-0047,ESEP,Space explorations of Planetary Environments(2010), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), and Agence Spatiale Européenne = European Space Agency (ESA)
Subjects: Astrochemistry, 010504 meteorology & atmospheric sciences, Comet, chemistry.chemical_element, Mass spectrometry, 01 natural sciences, Astrobiology, Ion, Jupiter, 0103 physical sciences, Organic matter, space vehicles: instruments, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, chemistry.chemical_classification, Physics, ta115, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], astrochemistry, comets: general, Astronomy and Astrophysics, Accretion (astrophysics), chemistry, 13. Climate action, Space and Planetary Science, techniques: miscellaneous, comets: individual: 67P/Churyumov-Gerasimenko, Carbon
Abstract: International audience; Cometary ices are rich in CO2, CO and organic volatile compounds, but the carbon content of cometary dust was only measured for the Oort Cloud comet 1P/Halley, during its flyby in 1986. The COmetary Secondary Ion Mass Analyzer (COSIMA)/Rosetta mass spectrometer analysed dust particles with sizes ranging from 50 to 1000 mu m, collected over 2 yr, from 67P/Churyumov-Gerasimenko (67P), a Jupiter family comet. Here, we report 67P dust composition focusing on the elements C and O. It has a high carbon content (atomic C/Si = 5.5(-1.2)(+1.4) on average) close to the solar value and comparable to the 1P/Halley data. From COSIMA measurements, we conclude that 67P particles are made of nearly 50 per cent organic matter in mass, mixed with mineral phases that are mostly anhydrous. The whole composition, rich in carbon and non-hydrated minerals, points to a primitive matter that likely preserved its initial characteristics since the comet accretion in the outer regions of the protoplanetary disc.
Published: 2017
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30. Similarities in element content between comet 67P/Churyumov–Gerasimenko coma dust and selected meteorite samples

Author: Sandra Siljeström, Oliver Stenzel, Franz Brandstätter, Martin Hilchenbach, John Paquette, Ludovic Ferrière, Sihane Merouane, Cécile Engrand, Peter Filzmoser, Kurt Varmuza, Christian Koeberl, Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Institute of Statistics and Mathematical Methods in Economics, Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Natural History Museum [Vienna] (NHM), and RISE Research Institutes of Sweden
Subjects: Physics, comets: individual: 67P/Churyumov–Gerasimenko, ta115, 010504 meteorology & atmospheric sciences, Meteoroid, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], Comet, Astronomy and Astrophysics, Coma (optics), 01 natural sciences, meteorites, Astrobiology, Meteorite, Space and Planetary Science, [SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry, 0103 physical sciences, meteors, meteoroids, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: International audience; We have analysed the element composition and the context of particles collected within the coma of 67P/Churyumov–Gerasimenko with Rosetta’s COmetary Secondary Ion Mass Analyzer (COSIMA). A comparison has been made between on board cometary samples and four meteorite samples measured in the laboratory with the COSIMA reference model. Focusing on the rock-forming elements, we have found similarities with chondrite meteorites for some ion count ratios. The composition of 67P/Churyumov–Gerasimenko particles measured by COSIMA shows an enrichment in volatile elements compared to that of the investigated Renazzo (CR2) carbonaceous meteorite sample.
Published: 2017
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31. Cosmic ray dose Monitoring using RadFET sensors of the Rosetta instruments SESAME and COSIMA

Author: H. Henkel, Martin Hilchenbach, Andreas Koch, Peter Falke, Henning Fischer, K. Thiel, Klaus J. Seidensticker, and Hans-Herbert Fischer
Subjects: Asteroiden und Kometen, 010504 meteorology & atmospheric sciences, Comet, Ionising dose, Aerospace Engineering, Cosmic ray, Astrophysics, Radiation, 01 natural sciences, Ionizing radiation, law.invention, Orbiter, law, 0103 physical sciences, Rosetta, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, Dosimeter, RadFET, Philae, SESAME, Charged particle, Nutzerzentrum für Weltraumexperimente (MUSC), COSIMA, Solar particle event
Abstract: On its more than 10 years journey to comet 67P/Churyumov–Gerasimenko, Rosetta carried RadFET ionising dose monitors in the central electronics of the orbiter instrument COSIMA and the lander instrument SESAME. The readings of the dosimeters were corrected for the temperature of the devices during measurements. Because the sensitivity of RadFETs depends on the energy of impinging charged particles, a mean efficiency factor for the prevalent proton radiation was determined by applying nine efficiency models to proton energy spectra of Rosetta's radiation environment. The resulting dose profiles show linear increases of the accumulated dose with time, mainly caused by galactic cosmic radiation, and the arrival of two solar particle events in 2005. The accumulated dose (in Silicon) during 3909 days in space from 2004-03-02 to 2014-11-14 was 3.2 ± 0.6 Gy in case of COSIMA and 1.9 ± 0.4 Gy for SESAME. The deviation of the two measurements is mainly due to the solar particle event in September 2005, which had a 5.3 ± 1.0 times stronger impact on the COSIMA RadFET. Measured dose levels are one order of magnitude lower than those expected before launch for not being exceeded on the 90% confidence level, which is mainly due to the low solar activity during the mission so far.
Published: 2016

32. The 75th Annual Meeting of the Meteoritical Society Cairns, Australia, 12-17 August, 2012

Author: Cecile Engrand, Martin Hilchenbach, Christelle Briois, R. Benoit, G. Briani, Henning Fischer, and Laurent Thirkell
Subjects: chemistry.chemical_classification, 010504 meteorology & atmospheric sciences, Earth science, CHON, 01 natural sciences, Astrobiology, Geophysics, chemistry, Space and Planetary Science, 0103 physical sciences, Organic matter, Antarctic snow, 010303 astronomy & astrophysics, Geology, 0105 earth and related environmental sciences
Abstract: We performed TOF-SIMS analyses of one UCAMM to investigate pristine organic matter and to determine if UCAMMs are representative of cometary CHON grains.
Published: 2012
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33. In situ analysis of Europa ices by short-range melting probes

Author: Jens Biele, Norbert I. Kömle, Martin Hilchenbach, and Stephan Ulamec
Subjects: Scientific instrument, Atmospheric Science, Solar System, Range (particle radiation), Instrumentation, Aerospace Engineering, Drilling, short-range melting probes, Astronomy and Astrophysics, Crust, Astrobiology, Geophysics, Space and Planetary Science, Planet, In situ analysis, General Earth and Planetary Sciences, Geology
Abstract: A key aspect for understanding the astrobiological potential of planets and moons in the Solar system is the analysis of material embedded in or underneath icy layers on the surface. In particular in case of the icy crust of Jupiters moon Europa such investigation would be of greatest interest. For a Europa lander to be launched in the 2020–2030 timeframe, we propose to use a simplified instrumented melting probe which is able to access and sample depths of a few meters without the necessity of heavy and complicated drilling equipment. While melting probes have successfully been used for terrestrial applications, e.g. in Antarctic ice, their behavior in vacuum and at very low temperatures is different and theory needs confirmation by tests. In an earlier work, the planetary simulation chamber at DLR in Cologne has been used to perform a series of melting tests in cold (LN2-cooled) water ice samples. The feasibility of the method could be demonstrated and the energy demand for a space mission was estimated. A simplified melting probe to access the uppermost meters of Europa’s crust appears to be feasible yet very demanding in terms of energy. The melting probe needs to be equipped with a suite of scientific instruments that are capable of determining the chemical and isotopic composition of the embedded or dissolved materials and which are indicative of organic material. An overview of potential instrumentation is given.
Published: 2011
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34. Structure of the heliosheath from HSTOF energetic neutral atoms measurements

Author: Maciej Bzowski, Martin Hilchenbach, J. Grygorczuk, K. C. Hsieh, Andrzej Czechowski, S. Grzedzielski, and J. M. Sokol
Subjects: Physics, Solar wind, 010504 meteorology & atmospheric sciences, Energetic neutral atom, Space and Planetary Science, 0103 physical sciences, Interplanetary medium, Astronomy and Astrophysics, Astrophysics, Atomic physics, 010303 astronomy & astrophysics, 01 natural sciences, 0105 earth and related environmental sciences
Abstract: Context. From the year 1996 until now, High energy Suprathermal Time Of Flight sensor (HSTOF) on board Solar and Heliospheric Observatory (SOHO) has been measuring the heliospheric energetic neutral atoms (ENA) flux between ±17° from the ecliptic plane. At present it is the only ENA instrument with the energy range within that of Voyager LECP energetic ion measurements. The energetic ion density and thickness of the inner heliosheath along the Voyager 1 trajectory are now known, and the ENA flux in the HSTOF energy range coming from the Voyager 1 direction may be estimated. Aims. We use HSTOF ENA data and Voyager 1 energetic ion spectrum to compare the regions of the heliosheath observed by HSTOF and Voyager 1. Methods. We compared the HSTOF ENA flux data from the forward and flank sectors of the heliosphere observed in various time periods between the years 1996 and 2010 and calculated the predicted ENA flux from the Voyager 1 direction using the Voyager 1 LECP energetic ion spectrum and including the contributions of charge exchange with both neutral H and He atoms. Results. The ratio between the HSTOF ENA flux from the ecliptic longitude sector 210−300° (the LISM apex sector) for the period 1996−1997 to the estimated ENA flux from the Voyager 1 direction is ∼1.3, but decreases to ∼0.6 for the period 1996−2005 and ∼0.3 for 1998−2006. For the flank longitude sectors (120−210° and 300−30°), the ratio also tends to decrease with time from ∼0.6 for 1996−2005 to ∼0.2 for 2008−2010. We discuss implications of these results for the energetic ion distribution in the heliosheath and the structure of the heliosphere.
Published: 2018
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35. THICKNESS OF THE HELIOSHEATH, RETURN OF THE PICK-UP IONS, AND VOYAGER 1 'S CROSSING THE HELIOPAUSE

Author: Martin Hilchenbach, K. C. Hsieh, Andrzej Czechowski, Stan Grzedzielski, József Kóta, and Joe Giacalone
Subjects: Particle acceleration, Shock wave, Physics, Proton, Energetic neutral atom, Space and Planetary Science, Ecliptic, Stellar atmosphere, Astronomy and Astrophysics, Astrophysics, Heliosphere, Charged particle
Abstract: Using results of remote sensing by energetic neutral atoms from IBEX, SOHO/HSTOF, and Cassini/INCA, in situ measurements of ~40-4000 keV protons in the heliosheath (HS) from Low Energy Charged Particle on Voyager 1 and Voyager 2, and outputs from numerical modeling of the termination shock, we estimate L, the characteristic thickness of the HS in the "upwind" direction (±45° in ecliptic longitude of the Nose at λ = 255°). A simple steady-state, internally consistent model gives L = 21 ± 6 AU for Voyager 1, L = 28 ± 8 AU for Voyager 2, and L = 25 ± 8 AU assuming that the same L value is valid for both spacecraft. We recognize that this is a very coarse cut at a very dynamic region of the heliosphere; but if the lower value L = 21 AU applies, one could expect Voyager 1 to cross the heliopause as early as late 2010.
Published: 2010
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36. Imaging the heliosheath using HSTOF energetic neutral atoms and Voyager 1 ion data

Author: S. Grzedzielski, Martin Hilchenbach, K. C. Hsieh, Andrzej Czechowski, and József Kóta
Subjects: Interstellar medium, Physics, Solar wind, Energetic neutral atom, Space and Planetary Science, Interplanetary medium, Astronomy and Astrophysics, Context (language use), Astrophysics, Atomic physics, Threshold energy, Heliosphere, Spectral line
Abstract: Context. Voyager 1 and 2 LECP instruments measure the distributions of the heliosheath ions of energies ≥40 keV. This threshold energy is an order of magnitude higher than the maximum energy (6 keV) of the energetic neutral atoms (ENA) to be measured by the forthcoming IBEX mission. On the other hand, the energy range of SOHO/CELIAS/HSTOF ENA measurements is 58−88 keV for H and 28−58 keV/n for He atoms, which overlaps with the energy range of Voyagers LECP. This offers a unique opportunity to combine HSTOF ENA measurements at 1 AU with LECP ion measurements in the heliosheath and obtain information about the large-scale structure of the heliosphere. Aims. We use energetic neutral atoms data at 1 AU and a Voyager 1 spectrum in the heliosheath to estimate the average column density of neutral hydrogen in selected sectors of the forward heliosheath. Methods. We reanalyzed the energetic neutral hydrogen and helium data from HSTOF to identify the contribution to the neutral atoms flux originating in directions close to the apex of the Sun’s motion relative to the local interstellar medium (LISM). We combine the data from HSTOF with the parent ion spectrum in the heliosheath measured by Voyager 1 to derive the background neutral hydrogen column density NH in the heliosheath and estimate the thickness L of the heliosheath within ±45 ◦ from the apex direction and in two 90 ◦ wide flank sectors. Results. In the forward sector of the heliosheath NH = (0.63 ± 0.19) × 10 14 cm −2 , corresponding to the thickness L = (42 ± 12 AU)/nH/(0. 1c m −3 )w herenH = average H density in the heliosheath. This is within the range of values predicted by theoretical models, but suggests that the heliosheath is thinner than expected. The hydrogen column densities in the flank sectors are not symmetric relative to the apex, but the difference is within the statistical uncertainty. The H/He ratio measured by HSTOF is lower than the value following from Voyager 1 heliosheath spectra.
Published: 2008
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37. Evidence for Iroshnikov-Kraichnan-Type Turbulence in the Solar Wind Upstream of Interplanetary Traveling Shocks

Author: R. Kallenbach, Peter Wurz, K. Bamert, Charles W. Smith, Martin Hilchenbach, and J. A. le Roux
Subjects: Physics, Shock wave, Turbulence, Waves in plasmas, Astrophysics::High Energy Astrophysical Phenomena, Astronomy, Astronomy and Astrophysics, Computational physics, Particle acceleration, Solar wind, Physics::Plasma Physics, Space and Planetary Science, Physics::Space Physics, Coronal mass ejection, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Earth and Planetary Astrophysics, Magnetohydrodynamics, Interplanetary spaceflight
Abstract: We analyze suprathermal ions and plasma wave spectra upstream of interplanetary shocks driven by coronal mass ejection events. In particular, we analyze the competition between two processes: (1) the upstream wave generation by suprathermal protons accelerated at the shock, and (2) the cascading of wave energy in the inertial range of solar wind turbulence. We derive the cascading timescale from the comparison of particle and turbulent wave spectra with theory and conclude that amplified solar wind turbulence upstream of interplanetary traveling shocks is better described by Iroshnikov-Kraichnan-type rather than Kolmogorov-type wave diffusion.
Published: 2008
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38. Dust particle flux and size distribution in the coma of 67P/Churyumov-Gerasimenko measured in situ by the COSIMA instrument on board Rosetta

Author: Martin Hilchenbach, N. Ligier, Marco Fulle, Yves Langevin, Jouni Rynö, Rita Schulz, Klaus Hornung, Sihane Merouane, Nicolas Altobelli, B. Zaprudin, Henning Fischer, Oliver Stenzel, Johan Silen, Alessandra Rotundi, Jochen Kissel, V. Della Corte, ITA, FRA, and DEU
Subjects: In situ, Physics, Comets: individual: 67P/Churyumov-Gerasimenko, Astronomy and Astrophysics, Space and Planetary Science, 010504 meteorology & atmospheric sciences, Astrophysics, 01 natural sciences, Power law, Ion, On board, Interplanetary dust cloud, 0103 physical sciences, Millimeter, Porosity, 010303 astronomy & astrophysics, Stratosphere, 0105 earth and related environmental sciences
Abstract: Context. The COmetary Secondary Ion Mass Analyzer (COSIMA) on board Rosetta is dedicated to the collection and compositional analysis of the dust particles in the coma of 67P/Churyumov-Gerasimenko (67P). Aims: Investigation of the physical properties of the dust particles collected along the comet trajectory around the Sun starting at a heliocentric distance of 3.5 AU. Methods: The flux, size distribution, and morphology of the dust particles collected in the vicinity of the nucleus of comet 67P were measured with a daily to weekly time resolution. Results: The particles collected by COSIMA can be classified according to their morphology into two main types: compact particles and porous aggregates. In low-resolution images, the porous material appears similar to the chondritic-porous interplanetary dust particles collected in Earth's stratosphere in terms of texture. We show that this porous material represents 75% in volume and 50% in number of the large dust particles collected by COSIMA. Compact particles have typical sizes from a few tens of microns to a few hundreds of microns, while porous aggregates can be as large as a millimeter. The particles are not collected as a continuous flow but appear in bursts. This could be due to limited time resolution and/or fragmentation either in the collection funnel or few meters away from the spacecraft. The average collection rate of dust particles as a function of nucleo-centric distance shows that, at high phase angle, the dust flux follows a 1/d2comet law, excluding fragmentation of the dust particles along their journey to the spacecraft. At low phase angle, the dust flux is much more dispersed compared to the 1/d2comet law but cannot be explained by fragmentation of the particles along their trajectory since their velocity, indirectly deduced from the COSIMA data, does not support such a phenomenon. The cumulative size distribution of particles larger than 150 μm follows a power law close to r- 0.8 ± 0.1, confirming measurements made by another Rosetta dust instrument Grain Impact Analyser and Dust Accumulator (GIADA). The cumulative size distribution of particles between 30 μm and 150 μm has a power index of -1.9 ± 0.3. The excess of dust in the 10-100 μm range in comparison to the 100 μm-1 mm range together with no evidence for fragmentation in the inner coma, implies that these particles could have been released or fragmented at the nucleus right after lift-off of larger particles. Below 30 μm, particles exhibit a flat size distribution. We interprete this knee in the size distribution at small sizes as the consequence of strong binding forces between the sub-constitutents. For aggregates smaller than 30 μm, forces stronger than Van-der-Waals forces would be needed to break them apart.
Published: 2016

39. A first assessment of the strength of cometary particles collected in-situ by the COSIMA instrument onboard ROSETTA

Author: Klaus Hornung, Sihane Merouane, Martin Hilchenbach, Yves Langevin, Eva Maria Mellado, Vincenzo Della Corte, Jochen Kissel, Cecile Engrand, Rita Schulz, Jouni Ryno, Johan Silen, null the COSIMA team, Institut für Strömungsmechanik und Aerodynamik (LRT-7), Universität der Bundeswehr München [Neubiberg], Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), Istituto Nazionale di Astrofisica (INAF), Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM AS), Université Paris-Saclay-Univ. Paris-Sud-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), ESA Scientific Support Office, European Space Agency (ESA), Finnish Meteorological Institute Observation Services, Finnish Meteorological Institute (FMI), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Italian Space Agency within the ASI-INAF agreements I/032/05/0 and I/024/12/0., COSIMA was built by a consortium led by the Max-Planck-Institut für Extraterrestrische Physik, Garching, Germany in collaboration with Laboratoire de Physique et Chimie de l'Environnement et de l'Espace, Orléans, France, Institut d'Astrophysique Spatiale, CNRS/Université Paris Sud, Orsay, France, Finnish Meteorological Institute, Helsinki, Finland, Universität Wuppertal, Wuppertal, Germany, von Hoerner und Sulger GmbH, Schwetzingen, Germany, Universität der Bundeswehr, Neubiberg, Germany, Institut für Physik, Forschungszentrum Seibersdorf, Seibersdorf, Austria, Institut für Weltraumforschung, Österreichische Akademie der Wissenschaften, Graz, Austria and is led by the Max-Planck-Institut für Sonnensystemforschung, Göttingen, Germany., ITA, FRA, and DEU
Subjects: In situ, Physics, Cometary dust, ta115, 010504 meteorology & atmospheric sciences, Spacecraft, Impact fragmentation, Mechanical strength, Rosetta mission, Astronomy and Astrophysics, Space and Planetary Science, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], business.industry, Dust particles, Comet, Astronomy, 01 natural sciences, Fragment size, 0103 physical sciences, Mass analyzer, business, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences
Abstract: COSIMA was built by a consortium led by the Max-Planck-Institut für Extraterrestrische Physik, Garching, Germany in collaboration with Laboratoire de Physique et Chimie de l'Environnement et de l'Espace, Orléans, France, Institut d'Astrophysique Spatiale, CNRS/Université Paris Sud, Orsay, France, Finnish Meteorological Institute, Helsinki, Finland, Universität Wuppertal, Wuppertal, Germany, von Hoerner und Sulger GmbH, Schwetzingen, Germany, Universität der Bundeswehr, Neubiberg, Germany, Institut für Physik, Forschungszentrum Seibersdorf, Seibersdorf, Austria, Institut für Weltraumforschung, Österreichische Akademie der Wissenschaften, Graz, Austria and is led by the Max-Planck-Institut für Sonnensystemforschung, Göttingen, Germany. The support of the national funding agencies of Germany (DLR, Grant 50 QP 1302), France (CNES), Austria, Finland and the ESA Technical Directorate; International audience; Soon after the arrival of the ROSETTA spacecraft at Comet 67/P Churyumov-Gerasimenko the onboard instrument COSIMA (“Cometary Secondary Ion Mass Analyzer”) collected a large number of cometary dust particles on targets from gold black of thickness between 10 and 30 μm. Inspection by its camera subsystem revealed that many of them consist of smaller units of typically some tens of micrometers in size. The collection process left the smaller dust particles in an essentially unaltered state whereas most particles larger than about 100 μm got fragmented into smaller pieces. Using the observed fragment size distributions, the present paper includes a first assessment of the strength for those dust particles that were disrupted upon impact.
Published: 2016
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40. High-molecular-weight organic matter in the particles of comet 67P/Churyumov–Gerasimenko

Author: Harald Krüger, Jochen Kissel, H. Henkel, Anais Bardyn, Albrecht Glasmachers, François-Régis Orthous-Daunay, Hervé Cottin, Elmar K. Jessberger, Eberhard Grün, Harry Lehto, François Raulin, Kirsi Lehto, Kurt Varmuza, Sihane Merouane, Nicolas Fray, H. Höfner, Yves Langevin, Luigi Colangeli, Laurent Thirkell, Kathrin Altwegg, Andreas Koch, Johan Silen, Gerhard Haerendel, Léna Le Roy, Jouni Rynö, Christelle Briois, Paola Modica, Oliver Stenzel, Klaus Torkar, Donia Baklouti, Karl-Peter Wanczek, Martin Hilchenbach, Thomas Stephan, John Paquette, R. Thomas, Rita Schulz, Klaus Hornung, Henning Fischer, Cécile Engrand, W. Steiger, Sandra Siljeström, B. Zaprudin, Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Center for Space and Habitability (CSH), University of Bern, Physikalisches Institut [Bern], Universität Bern [Bern], Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM AS), Université Paris-Saclay-Univ. Paris-Sud-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Climate and Environmental Physics [Bern] (CEP), Universität Bern [Bern]-Universität Bern [Bern], Max-Planck-Institut für Kernphysik (MPIK), Max-Planck-Gesellschaft, Institut für Strömungsmechanik und Aerodynamik (LRT-7), Universität der Bundeswehr München [Neubiberg], Max Planck Institute for Solar System Research (MPS), Tuorla Observatory, University of Turku, Max-Planck-Institut für Sonnensystemforschung (MPS), 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]), Finnish Meteorological Institute Observation Services, Finnish Meteorological Institute (FMI), Department of Chemistry, Materials and Surfaces [Boras], SP Technical Research Institute of Sweden, Department of Geophysical Sciences [Chicago], University of Chicago, Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Universität Bern [Bern] (UNIBE), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Univ. Paris-Sud, Universität Bern [Bern] (UNIBE)-Universität Bern [Bern] (UNIBE), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Institut national des sciences de l'Univers (INSU - CNRS), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), 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), Laboratoire inter-universitaire des systèmes atmosphèriques ( LISA ), Institut national des sciences de l'Univers ( INSU - CNRS ) -Université Paris Diderot - Paris 7 ( UPD7 ) -Université Paris-Est Créteil Val-de-Marne - Paris 12 ( UPEC UP12 ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace ( LPC2E ), Centre National de la Recherche Scientifique ( CNRS ) -Université d'Orléans ( UO ) -Institut national des sciences de l'Univers ( INSU - CNRS ), Center for Space and Habitability ( CSH ), Institut d'astrophysique spatiale ( IAS ), Université Paris-Sud - Paris 11 ( UP11 ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Centre National de la Recherche Scientifique ( CNRS ), European Space Research and Technology Centre ( ESTEC ), European Space Agency ( ESA ), Centre de Sciences Nucléaires et de Sciences de la Matière ( CSNSM AS ), Université Paris-Saclay-Univ. Paris-Sud-CNRS/IN2P3, Climate and Environmental Physics [Bern], Max-Planck-Institut für Kernphysik ( MPIK ), Institut für Strömungsmechanik und Aerodynamik ( LRT-7 ), Max Planck Institute for Solar System Research ( MPS ), Max-Planck-Institut für Sonnensystemforschung ( MPS ), Institut de Planétologie et d'Astrophysique de Grenoble ( IPAG ), Observatoire des Sciences de l'Univers de Grenoble ( OSUG ), 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 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 ) -Centre National de la Recherche Scientifique ( CNRS ), Laboratoire Magmas et Volcans ( LMV ), Université Blaise Pascal - Clermont-Ferrand 2 ( UBP ) -Institut national des sciences de l'Univers ( INSU - CNRS ) -Université Jean Monnet [Saint-Étienne] ( UJM ) -Centre National de la Recherche Scientifique ( CNRS ), P.O. Box 1870, Nordnes, Institute of Marine Research, Science Faculty, Department Biology, Padualaan 8, Utrecht University [Utrecht], The University of Chicago, Department of the Geophysical Sciences ( THE UNIVERSITY OF CHICAGO ), and The Univerity of Chicago, Department of the Geophysical Sciences
Subjects: chemistry.chemical_classification, Multidisciplinary, ta115, 010504 meteorology & atmospheric sciences, Hydrogen, Comet dust, chemistry.chemical_element, Methods• References• Acknowledgements• Author information• Extended data figures and tables, 01 natural sciences, Astrobiology, Interstellar medium, chemistry, Meteorite, 13. Climate action, [SDU]Sciences of the Universe [physics], Carbonaceous chondrite, 0103 physical sciences, Sublimation (phase transition), Organic matter, Formation and evolution of the Solar System, 010303 astronomy & astrophysics, [ SDU ] Sciences of the Universe [physics], 0105 earth and related environmental sciences
Abstract: International audience; The presence of solid carbonaceous matter in cometary dust was established by the detection of elements such as carbon, hydrogen, oxygen and nitrogen in particles from comet 1P/Halley1, 2. Such matter is generally thought to have originated in the interstellar medium3, but it might have formed in the solar nebula—the cloud of gas and dust that was left over after the Sun formed4. This solid carbonaceous material cannot be observed from Earth, so it has eluded unambiguous characterization5. Many gaseous organic molecules, however, have been observed6, 7, 8, 9; they come mostly from the sublimation of ices at the surface or in the subsurface of cometary nuclei8. These ices could have been formed from material inherited from the interstellar medium that suffered little processing in the solar nebula10. Here we report the in situ detection of solid organic matter in the dust particles emitted by comet 67P/Churyumov–Gerasimenko; the carbon in this organic material is bound in very large macromolecular compounds, analogous to the insoluble organic matter found in the carbonaceous chondrite meteorites11, 12. The organic matter in meteorites might have formed in the interstellar medium and/or the solar nebula, but was almost certainly modified in the meteorites’ parent bodies11. We conclude that the observed cometary carbonaceous solid matter could have the same origin as the meteoritic insoluble organic matter, but suffered less modification before and/or after being incorporated into the comet.
Published: 2016
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41. Variations in cometary dust composition from Giotto to Rosetta, clues to their formation mechanisms

Author: Yves Langevin, John Paquette, Jean Duprat, Johan Silen, Rita Schulz, Jouni Rynö, Martin Hilchenbach, Emmanuel Dartois, Laurent Thirkell, Karim Benzerara, Anais Bardyn, Nicolas Fray, Oliver Stenzel, Henning Fischer, M. Godard, Hervé Cottin, Donia Baklouti, Christelle Briois, Hugues Leroux, Cécile Engrand, Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM AS), Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Université Paris-Saclay-Univ. Paris-Sud, Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS), Unité Matériaux et Transformations - UMR 8207 (UMET), Institut National de la Recherche Agronomique (INRA)-Ecole Nationale Supérieure de Chimie de Lille (ENSCL)-Institut de Chimie du CNRS (INC)-Université de Lille-Centre National de la Recherche Scientifique (CNRS), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Max-Planck-Gesellschaft, Centre de Sciences Nucléaires et de Sciences de la Matière (CSNSM), Université Paris-Sud - Paris 11 (UP11)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Finnish Meteorological Institute (FMI), ESA Scientific Support Office, Agence Spatiale Européenne = European Space Agency (ESA), ANR-10-IDEX-0001,PSL,Paris Sciences et Lettres(2010), ANR-11-BS56-0026,OGRESSE,Grains cométaires et évolution du système solaire primitif : analyses isotopiques de micrométéorites polaires cométaires(2011), Université de Lille, ENSCL, CNRS, INRA, Unité Matériaux et Transformations - UMR 8207 [UMET], Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut de recherche pour le développement [IRD] : UR206-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Université Pierre et Marie Curie - Paris 6 (UPMC), Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Ecole Nationale Supérieure de Chimie de Lille (ENSCL)-Institut National de la Recherche Agronomique (INRA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, PSL Research University (PSL)-PSL Research University (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Centre National de la Recherche Scientifique (CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Institut national des sciences de l'Univers (INSU - CNRS), Max-Planck-Institut für Sonnensystemforschung (MPS), European Space Agency (ESA), ANR-10-IDEX-0001/10-LABX-0047,ESEP,Space explorations of Planetary Environments(2010), Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Saclay-Univ. Paris-Sud-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut de recherche pour le développement [IRD] : UR206-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), and Institut de Chimie du CNRS (INC)-Institut National de la Recherche Agronomique (INRA)-Centre National de la Recherche Scientifique (CNRS)-Université de Lille-Ecole Nationale Supérieure de Chimie de Lille (ENSCL)
Subjects: Extinction (astronomy), Comet, Interplanetary medium, 010502 geochemistry & geophysics, 01 natural sciences, meteorites, Astrobiology, Interplanetary dust cloud, Chondrite, 0103 physical sciences, meteors, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Physics, ta115, Meteoroid, [SDU.ASTR]Sciences of the Universe [physics]/Astrophysics [astro-ph], extinction, Astronomy and Astrophysics, [PHYS.PHYS.PHYS-SPACE-PH]Physics [physics]/Physics [physics]/Space Physics [physics.space-ph], Interstellar medium, Meteorite, 13. Climate action, Space and Planetary Science, meteoroids comets: general minor planets, asteroids: general interplanetary medium ISM: abundances dust
Abstract: International audience; This paper reviews the current knowledge on the composition of cometary dust (ice, minerals and organics) in order to constrain their origin and formation mechanisms. Comets have been investigated by astronomical observations, space missions (Giotto to Rosetta), and by the analysis of cometary dust particles collected on Earth, chondritic porous interplanetary dust particles (CP-IDPs) and ultracarbonaceous Antarctic micrometeorites (UCAMMs). Most ices detected in the dense phases of the interstellar medium (ISM) have been identified in cometary volatiles. However, differences also suggest that cometary ices cannot be completely inherited from the ISM. Cometary minerals are dominated by crystalline Mg-rich silicates, Fe sulphides and glassy phases including GEMS (glass with embedded metals and sulphides). The crystalline nature and refractory composition of a significant fraction of the minerals in comets imply a high temperature formation/processing close to the proto-Sun, resetting a possible presolar signature of these phases. These minerals were further transported up to the external regions of the disc and incorporated in comet nuclei. Cometary matter contains a low abundance of isotopically anomalous minerals directly inherited from the presolar cloud. At least two different kinds of organic matter are found in dust of cometary origin, with low or high nitrogen content. N-poor organic matter is also observed in primitive interplanetary materials (like carbonaceous chondrites) and its origin is debated. The N-rich organic matter is only observed in CP-IDPs and UCAMMs and can be formed by Galactic cosmic ray irradiation of N2- and CH4-rich icy surface at large heliocentric distance beyond a ‘nitrogen snow line’.
Published: 2016
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42. The nonmagnetic nucleus of comet 67P/Churyumov-Gerasimenko

Author: Martin Hilchenbach, Philip Heinisch, Anita Przyklenk, Holger Sierks, A. P. Remizov, Karl-Heinz Glassmeier, Gerhard Haerendel, Carsten Güttler, Hans-Ulrich Auster, David Hercik, Uwe Motschmann, G. Berghofer, Christopher T. Russell, Ingo Richter, Konrad Schwingenschuh, Ekkehard Kührt, Karl-Heinz Fornacon, Istvan Apathy, Werner Magnes, Chris Carr, Science and Technology Facilities Council (STFC), and Science and Technology Facilities Council [2006-2012]
Subjects: SAMPLES, General Science & Technology, Magnetometer, ROSETTA PLASMA CONSORTIUM, Comet, ASTEROIDS, DUST, ENCOUNTER, Astrophysics, law.invention, Magnetization, comet, nonmagnetic nucleus, law, GASPRA, ROMAP, Physics, Science & Technology, 67P, Multidisciplinary, Magnetic moment, METEORITES, GIOTTO MAGNETOMETER EXPERIMENT, Magnetic field, Multidisciplinary Sciences, MAGNETIC-FIELD OBSERVATIONS, Dipole, Asteroid, Science & Technology - Other Topics, Astrophysics::Earth and Planetary Astrophysics, Formation and evolution of the Solar System, SOLAR-NEBULA
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 −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.
Published: 2015
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43. DENSITY AND CHARGE OF PRISTINE FLUFFY PARTICLES FROM COMET 67P/CHURYUMOV–GERASIMENKO

Author: Nicolas Altobelli, J. M. Jeronimo, Martin Hilchenbach, Philippe Lamy, Sihane Merouane, F. Lucarelli, M. Herranz, Mark Leese, Bo Å. S. Gustafson, M. Cosi, Stavro Ivanovski, Eberhard Grün, Vito Mennella, Jose Luis Ortiz, M. Ferrari, V. V. Zakharov, A. Lopez-Jimenez, Ernesto Palomba, Paul R. Weissman, Alessandra Rotundi, Roberto Sordini, Luigi Colangeli, R. Morales, J. E. Rodriguez, A. Molina, Mario Accolla, Francesca Esposito, V. Della Corte, Rafael Rodrigo, F. Giovane, J. A. M. McDonnell, J. J. López-Moreno, E. Mazzotta Epifani, Marco Fulle, John C. Zarnecki, Antal Juhász, F. Moreno, Pasquale Palumbo, E. Bussoletti, Simon F. Green, Karoly Szego, INAF - Osservatorio Astronomico di Trieste (OAT), Istituto Nazionale di Astrofisica (INAF), Universita degli studi di Napoli 'Parthenope' [Napoli], Planetary Science Institute [Tucson] (PSI), Institute of Astronomy [Cambridge], University of Cambridge [UK] (CAM), Wigner Research Centre for Physics [Budapest], Hungarian Academy of Sciences (MTA), 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), INAF - Osservatorio Astronomico di Capodimonte (OAC), INAF - Osservatorio Astrofisico di Catania (OACT), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, 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), Département d'Astrophysique (ex SAP) (DAP), Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, European Space Research and Technology Centre (ESTEC), European Space Agency (ESA), Istituto di Astrofisica e Planetologia Spaziali - INAF (IAPS), Max-Planck-Institut für Kernphysik (MPIK), British Geological Survey [Edinburgh], British Geological Survey (BGS), Centro de Astrobiologia [Madrid] (CAB), Instituto Nacional de Técnica Aeroespacial (INTA)-Consejo Superior de Investigaciones Científicas [Madrid] (CSIC), Leonardo, Virginia Polytechnic Institute and State University [Blacksburg], University of the Basque Country/Euskal Herriko Unibertsitatea (UPV/EHU), School of Physical Sciences [Milton Keynes], Faculty of Science, Technology, Engineering and Mathematics [Milton Keynes], The Open University [Milton Keynes] (OU)-The Open University [Milton Keynes] (OU), European Space Astronomy Centre (ESAC), Università degli Studi di Napoli 'Parthenope' = University of Naples (PARTHENOPE), 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), and Agence Spatiale Européenne = European Space Agency (ESA)
Subjects: Physics, [PHYS]Physics [physics], Brightness, individual (67P/Churyumov-Gerasimenko) - space vehicles, Comet, Astronomy, Astronomy and Astrophysics, Coma (optics), general - comets, Astrophysics, Bulk density, 13. Climate action, Space and Planetary Science, instruments, comets, Negative potential, Formation and evolution of the Solar System, [PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph], Refractory (planetary science), ComputingMilieux_MISCELLANEOUS, Cosmic dust
Abstract: The Grain Impact Analyzer and Dust Accumulator (GIADA) instrument on board ESA’s Rosetta mission is constraining the origin of the dust particles detected within the coma of comet 67 P/Churyumov–Gerasimenko (67P). The collected particles belong to two families: (i) compact particles (ranging in size from 0.03 to 1 mm), witnessing the presence of materials that underwent processing within the solar nebula and (ii) fluffy aggregates (ranging in size from 0.2 to 2.5 mm) of sub-micron grains that may be a record of a primitive component, probably linked to interstellar dust. The dynamics of the fluffy aggregates constrain their equivalent bulk density to -3. These aggregates are charged, fragmented, and decelerated by the spacecraft negative potential and enter GIADA in showers of fragments at speeds -1. The density of such optically thick aggregates is consistent with the low bulk density of the nucleus. The mass contribution of the fluffy aggregates to the refractory component of the nucleus is negligible and their coma brightness contribution is less than 15%.
Published: 2015
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44. Estimating the Thickness of the Heliosheath from CELIAS/HSTOF and Voyager 1 Data

Author: József Kóta, K. C. Hsieh, Reinald Kallenbach, Martin Hilchenbach, and Andrzej Czechowski
Subjects: Shock wave, Physics, Hydrogen, Ecliptic, Astronomy, Interplanetary medium, chemistry.chemical_element, Astronomy and Astrophysics, Particle acceleration, Solar wind, chemistry, Space and Planetary Science, Atomic physics, Helium, Heliosphere
Abstract: We use recent Voyager 1 measurements of the ion fluxes beyond the termination shock and the SOHO HSTOF/CELIAS measured fluxes of the energetic neutral hydrogen and helium at 1 AU to estimate the neutral hydrogen column density NH in the heliosheath. Our best estimate is NH = 1.13 × 1014 cm-2. The result corresponds to an average thickness of the heliosheath, in the forward part of the heliosphere (within 155° from the nose direction and 17° from the ecliptic), of L ~ 75 AU for an average hydrogen density of nH = 0.1 cm-3 in the heliosheath.
Published: 2006
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45. Rosetta Lander—Philae: Implications of an alternative mission

Author: Stephan Ulamec, D. Moura, H. Rosenbauer, B. Feuerbacher, S. Espinasse, H. Scheuerle, R. Willnecker, and Martin Hilchenbach
Subjects: Scientific instrument, Spacecraft, biology, business.industry, Comet, Rendezvous, Aerospace Engineering, Venus, biology.organism_classification, Astrobiology, Comet nucleus, Environmental science, business, Landing gear
Abstract: “Rosetta” is a Cornerstone Mission of the Horizon 2000 ESA Programme. Its goal is to rendezvous with a comet and to study its nucleus and coma using an orbiting spacecraft and a landed platform. The latter is called Philae; the Rosetta Lander has been designed to land softly on the comet nucleus and is equipped with 10 scientific instruments to perform in situ studies of cometary material. The Lander system is provided by international consortium with the participation of Germany, France, Italy, United Kingdom, Finland, Ireland, Hungary and Austria. The original Rosetta mission was planned to launch in January 2003 to reach comet 47P/Wirtanen in 2011 at a heliocentric distance of about 3 AU. Due to uncertainties regarding the reliability of the Ariane 5 launcher (after a catastrophic failure in December 2002) the Rosetta launch was postponed and a new mission studied. Changed mission characteristics (e.g. in launcher capacity; no swing-by at Venus) strongly limited the number of possible alternatives. After careful investigation, a decision was taken for a mission to comet 67/P Churyumov-Gerasimenko with a launch date in February 2004 and rendezvous in 2014. This new mission scenario has significant consequences for the Rosetta Lander, because the nucleus of P/Churyumov-Gerasimenko is expected to be considerably larger than that of P/Wirtanen. Current best estimates assume a radius of about 2.0 km and, thus, a mass which is about two orders of magnitude larger than that of the original target comet. This impacts strongly on the Lander separation, descent and landing scenario. Analysis of the increased landing risk on P/Churyumov-Gerasimenko has led to modifications of the landing gear to cope with the increased impact velocities expected.
Published: 2006
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46. Observation of energy-dependent ionic charge states in impulsive solar energetic particle events

Author: Berndt Klecker, L. M. Kistler, Mark A. Popecki, Martin Hilchenbach, Eberhard Möbius, and Harald Kucharek
Subjects: Physics, Atmospheric Science, Range (particle radiation), Astrophysics::High Energy Astrophysical Phenomena, Aerospace Engineering, Astronomy and Astrophysics, Electron, Corona, Ion, Impact ionization, Geophysics, Ionic potential, Space and Planetary Science, Physics::Space Physics, General Earth and Planetary Sciences, Particle, Atomic physics, Adiabatic process
Abstract: We measured the mean ionic charge state of Fe in several 3 He-rich and heavy-ion rich energetic particle events during the time period 1998–2000. We combined the ionic charge measurements of CELIAS/STOF onboard SOHO (10–100 keV/nuc) with the measurements of SEPICA onboard ACE (180–550 keV/nuc) to investigate the ionic charge distribution of Fe over a wide energy range. Whereas the mean ionic charge of Fe, Q m (Fe), increases strongly with energy from ∼14–16 at 180–250 keV/nuc to ∼16–20 at 350–550 keV/nuc, the mean ionic charge at lower energies of 10–100 keV/nuc was found to be significantly lower (12.5 ± 0.9). A comparison of the results with steady-state models that include impact ionization by protons and electrons in the low corona shows that the measured increase of Q m (Fe) with energy is often steeper than predicted by the model, and other effects, as for example adiabatic deceleration during the propagation, may play an important role.
Published: 2006
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47. On the 'injection problem' at the solar wind termination shock

Author: R. Kallenbach, J. A. le Roux, S. V. Chalov, Martin Hilchenbach, and K. Bamert
Subjects: Physics, Convection, Astrophysics::High Energy Astrophysical Phenomena, Astronomy and Astrophysics, Cosmic ray, Fermi acceleration, Astrophysics, Shock (mechanics), Momentum diffusion, Solar wind, Space and Planetary Science, Physics::Space Physics, Astrophysics::Solar and Stellar Astrophysics, Diffusion (business), Heliosphere
Abstract: This article presents an integrated analytical model on the injection efficiencies of the different ion species of the Anomalous component of the Cosmic Rays (ACRs) at the solar wind termination shock. We find that the injection into diffusive (first-order Fermi) acceleration is dominated by parallel ion diffusion and not by perpendicular diffusion unless the angle Ψ between the shock normal and the heliospheric magnetic field is almost exactly 90° (89.3° < T 90°). In steady state the threshold speed for injection into first-order Fermi acceleration at a not exactly perpendicular solar wind termination shock - with the Parker shock angle Ψ 89.3° - adjusts itself self-consistently. Increased anisotropic ACR flux amplifies Alfvenic turbulence which in turn suppresses parallel diffusion. It therefore increases the injection threshold and decreases the ACR flux until equilibrium is reached. For this equilibrium situation, we estimate the injection efficiencies of different species of suprathermal ions at the termination shock. We consider the following pre-acceleration processes: 1) momentum diffusion in compressional (ion-acoustic and magnetosonic) turbulence in the upstream supersonic solar wind and adiabatic cooling during convection to the termination shock; 2) reflection, transmission, and acceleration in the electric potential of the termination shock; and 3) momentum diffusion (stochastic or second-order Fermi acceleration) in the subsonic solar wind downstream of the termination shock in the inner heliosheath region. Our model results are compared to data from instruments on board the SOHO, ACE, Ulysses, and Voyager spacecraft.
Published: 2005
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48. Heliospheric energetic neutral atoms as a means to determine the anomalous cosmic ray spectrum at the termination shock

Author: Martin Hilchenbach, Andrzej Czechowski, and K. C. Hsieh
Subjects: Shock wave, Physics, Energetic neutral atom, Astrophysics::High Energy Astrophysical Phenomena, Spectrum (functional analysis), Interplanetary medium, Astronomy and Astrophysics, Cosmic ray, Astrophysics, Shock (mechanics), Solar wind, Space and Planetary Science, Physics::Space Physics, Heliosphere
Abstract: We demonstrate the possibility of deriving the anomalous cosmic ray (ACR) spectrum at the solar wind termination shock and the strength of the shock using energetic neutral H and He atoms (ENA) measurements at 1 AU. Assuming that the energetic neutral atoms detected by CELIAS/HSTOF on board SOHO are of ACR origin, we consider $\chi^2$ fits to the ACR termination shock spectrum based on approximations to the ACR distribution downstream of the shock. We show that the method becomes much more effective when the low-energy ENA data are combined with the available high-energy ACR data from Voyager spacecraft. The results imply a weak termination shock (compression ratio $\sim2.9$).
Published: 2005
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49. Hydromagnetic Wave Excitation Upstream of an Interplanetary Traveling Shock

Author: Charles W. Smith, Toshio Terasawa, Norman F. Ness, Martin Hilchenbach, Robert F. Wimmer-Schweingruber, R. Kallenbach, K. Bamert, and Berndt Klecker
Subjects: Physics, Shock wave, Range (particle radiation), Meteorology, Astrophysics::High Energy Astrophysical Phenomena, Interplanetary medium, Astronomy and Astrophysics, Magnetic field, Computational physics, Shock (mechanics), Solar wind, Space and Planetary Science, Physics::Space Physics, Coronal mass ejection, Astrophysics::Solar and Stellar Astrophysics, Interplanetary spaceflight
Abstract: Using data of the Highly Suprathermal Time-Of-Flight sensor of the Charge, Element, and Isotope Analysis System on board the Solar and Heliospheric Observatory spacecraft located at Lagrangian point L1 near Earth, we have measured proton spectra in the energy range 60 keV-2 MeV associated with the Bastille Day coronal mass ejection of 2000 July 14-16. For the same event, the power spectral densities of the magnetic field fluctuations in the solar wind have been measured with the magnetometer on board the Advanced Composition Explorer in the frequency range from about 0.05 mHz to 0.5 Hz. Within 0.11 AU upstream of the main shock, the flux of protons in the energy range 150 keV-2 MeV decreases much more rapidly with distance from the shock than is expected from diffusion in typical solar wind magnetic turbulence. In the same upstream region, the excitation of hydromagnetic waves in the frequency range 0.25-3 mHz and with power spectral density levels of up to 100 times the typical levels in the ambient solar wind is observed.
Published: 2004
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50. Anomalous helium ions as the source of energetic helium atoms in the outer heliosphere

Author: K. C. Hsieh, József Kóta, A. Shaw, Martin Hilchenbach, and A. Czechowski
Subjects: Physics, Atmospheric Science, Energetic neutral atom, Hydrogen, Aerospace Engineering, Flux, chemistry.chemical_element, Astronomy and Astrophysics, Cosmic ray, Ion, Solar wind, Geophysics, chemistry, Space and Planetary Science, Physics::Space Physics, Physics::Atomic and Molecular Clusters, General Earth and Planetary Sciences, Physics::Atomic Physics, Atomic physics, Heliosphere, Helium
Abstract: The helium component of the anomalous cosmic rays (ACR) is a potential source of neutral energetic helium due to charge-exchange of the He+ ions with the hydrogen or helium atoms from the background. The most effective source of the energetic helium atoms should correspond to the relatively low-energy (up to 100 keV/n) ions present in the regions near and beyond the solar wind termination shock. The energetic neutral atoms (ENA) of ACR origin are therefore generated in the distant heliosphere and can provide a means of remote observation of this region. We present the results of numerical calculations of the anomalous helium spectrum and spatial density in a model heliosphere and of the corresponding energetic helium flux. The results are compared with the data obtained by SOHO. We point out that the helium data, covering different region of energy-per-nucleon values, are an important supplement to the hydrogen SOHO data and can be used to test the hypotheses about the origin of the signal.
Published: 2004
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