On the Inorganic Composition of Cometary Dust from Comet 67P/Churyumov-Gerasimenko, as Seen by COSIMA on Board ROSETTA.
Cécile Engrand1, Donia Baklouti2, Christelle Briois3, Hervé Cottin4, Henning Fischer5, Nicolas Fray4, Marie Godard1, Hartmut Henkel6, Martin Hilchenbach5, Klaus Hornung7, Jochen Kissel5, Andreas Koch6, Yves Langevin8, Harry Lehto9, Sihane Merouane5, François-Régis Orthous-Daunay10, Jouni Rynö11, Rita Schulz12, Johan V Silen11, Sandra Siljeström13, Thomas Stephan14, Laurent Thirkell3, Kurt Varmuza15 and COSIMA Team, (1)Centre de Sciences Nucléaires et de Sciences de la Matiere - CSNSM, 91405 Orsay, France, (2)IAS Institut d'Astrophysique Spatiale, Orsay Cedex, France, (3)Laboratoire de Physique et Chimie de l'Environnement et de l'Espace, CNRS / Université d’Orléans, Orléans, France, (4)LISA Laboratoire Interuniversitaire des Systèmes Atmosphériques, Créteil, France, (5)Max Planck Institute for Solar System Research, Göttingen, Germany, (6)von Hoerner und Sulger GmbH, 68723 Schwetzingen, Germany, (7)Universität der Bundeswehr, 85577 Neubiberg, Germany, (8)Institut d'Astrophysique Spatiale, CNRS/Université Paris Saclay, Orsay Cedex, France, (9)University of Turku, Department of Physics and Astronomy, Tuorla Observatory, Piikkiö, Finland, (10)IPAG - Institut de Planetologie et d'Astrophysique de Grenoble, Grenoble, France, (11)Finnish Meteorological Institute, Helsinki, Finland, (12)European Space Agency, Noordwijk, Netherlands, (13)RISE Research Institutes of Sweden, Stockholm, Sweden, (14)The University of Chicago, Chicago, United States, (15)Technische Universität Wien, Wien, Austria
Abstract:
Analyses of cometary grains from comet 1P/Halley by the Giotto and Vega missions showed a composition of cometary dust dominated by organic matter associated to rock forming elements (Mg, Si, Fe) in varying amounts ("CHON" grains) [e.g. Kissel and Krueger, 1987; Kissel et al., 1986]. Ultracarbonaceous Antarctic micrometeorites (UCAMMs) discovered in the Japanese and French micrometeorite collections could be representatives of these CHON particles [Nakamura et al., 2005; Duprat et al., 2010]. On the other hand, samples from comet 81P/Wild 2 brought back in 2006 by the Stardust mission contain a large diversity of minerals with varying degrees of primitivity. Organic compounds were only found in small amounts, most probably as a result of degradation during high speed capture of the samples, but several forms of organic matter were identified at the sub-micron level, and glycine was also detected [Brownlee, 2014 and references therein]. The complex shape of comet 67P/Churyumov-Gerasimenko suggests that even more diversity in dust composition could be expected than in previous analyses of cometary samples.
The COSIMA dust analyzer on the ROSETTA spacecraft will analyze the dust from comet 67P/Churyumov-Gerasimenko [Kissel et al., 2009 and Hilchenbach et al., this conference]. In the high mass resolution time-of-flight spectra of COSIMA, the inorganic compounds are generally resolved from the organic contributions. We will report on the first results on the inorganic part of the spectra, and on its association with the organic phases [see Briois et al., this conference].
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