P41C-3934:
On the Inorganic Composition of Cometary Dust from Comet 67P/Churyumov-Gerasimenko, as Seen by COSIMA on Board ROSETTA.

Thursday, 18 December 2014
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 Langevin2, Harry Lehto8, Sihane Merouane5, François-Régis Orthous-Daunay9, Jouni Rynö10, Rita Schulz11, Johan V Silen10, Sandra Siljeström12, Thomas Stephan13, Laurent Thirkell3 and Kurt Varmuza14, (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, 45071 Orléans, France, (4)LISA Laboratoire Interuniversitaire des Systèmes Atmosphériques, CRETEIL, France, (5)Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany, (6)von Hoerner und Sulger GmbH, 68723 Schwetzingen, Germany, (7)Universität der Bundeswehr, 85577 Neubiberg, Germany, (8)University of Turku, Turku, Finland, (9)IPAG - Institut de Planetologie et d'Astrophysique de Grenoble, Grenoble, France, (10)Finnish Meteorological Institute, Helsinki, Finland, (11)European Space Research and Technology Centre, Noordwijk, Netherlands, (12)SP Technical Research Institute of Sweden, Borås, Sweden, (13)The University of Chicago, Chicago, United States, (14)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].

References: Brownlee D. (2014) Ann. Rev. Earth Planet. Sci., 42(1), 179-205. Duprat J. et al. (2010) Science, 328(5979), 742-745. Kissel J. and F. R. Krueger (1987) Nature, 326, 755-760. Kissel J. et al. (1986) Nature, 321, 336-337. Kissel J. et al. (2009) in "ROSETTA : ESA's Mission to the Origin of the Solar System", R. Schulz et al. (Eds), 201-242, Springer Science, New York. Nakamura T. et al. (2005) Meteoritics Planet. Sci., 40 Suppl., #5046.