Measuring Organic Matter with COSIMA on Board Rosetta

Wednesday, 17 December 2014: 2:40 PM
Christelle Briois1, Donia Baklouti2, Anais Bardyn1,3, Hervé Cottin3, Cécile Engrand4, Henning Fischer5, Nicolas Fray3, Marie Godard4, Martin Hilchenbach5, Hanna von Hoerner6, Herwig Höfner7, Klaus Hornung8, Jochen Kissel5, Yves Langevin2, Léna Le Roy9, Harry Lehto10, Kirsi Lehto10, François-Régis Orthous-Daunay11, Claire Revillet1, Jouni Rynö12, Rita Schulz13, Johan V Silen12, Sandra Siljeström14 and Laurent Thirkell1, (1)Laboratoire de Physique et Chimie de l'Environnement et de l'Espace, LPC2E, Orléans Cedex 2, France, (2)IAS Institut d'Astrophysique Spatiale, Orsay Cedex, France, (3)LISA Laboratoire Interuniversitaire des Systèmes Atmosphériques, CRETEIL, France, (4)Centre de Sciences Nucléaires et de Sciences de la Matiere - CSNSM, 91405 Orsay, France, (5)Max Planck Institute for Solar System Research, Katlenburg-Lindau, Germany, (6)von Hoerner und Sulger GmbH, Schwetzingen, Germany, (7)The Max Planck Institute for Extraterrestrial Physics, Garching, Germany, (8)Universität der Bundeswehr, 85577 Neubiberg, Germany, (9)University of Bern, Bern, Switzerland, (10)University of Turku, Turku, Finland, (11)IPAG - Institut de Planetologie et d'Astrophysique de Grenoble, Grenoble, France, (12)Finnish Meteorological Institute, Helsinki, Finland, (13)European Space Research and Technology Centre, Noordwijk, Netherlands, (14)SP Technical Research Institute of Sweden, Borås, Sweden
Comets are believed to contain the most pristine material of our Solar System materials and therefore to be a key to understand the origin of the Solar System, and the origin of life. Remote sensing observations have led to the detection of more than twenty simple organic molecules (Bockelée-Morvan et al., 2004; Mumma and Charnley, 2011). Experiments on-board in-situ exploration missions Giotto and Vega and the recent Stardust sample return missions have shown that a significant fraction of the cometary grains consists of organic matter. Spectra showed that both the gaseous (Mitchell et al., 1992) and the solid phase (grains) (Kissel and Krueger, 1987) contained organic molecules with higher masses than those of the molecules detected by remote sensing techniques in the gaseous phase. Some of the grains analyzed in the atmosphere of comet 1P/Halley seem to be essentially made of a mixture of carbon, hydrogen, oxygen and nitrogen (CHON grains, Fomenkova, 1999). Rosetta is an unparalleled opportunity to make a real breakthrough into the nature of cometary matter, both in the gas and in the solid phase. The dust mass spectrometer COSIMA on Rosetta will analyze organic and inorganic phases in the dust. The organic phases may be refractory, but some organics may evaporate with time from the dust and lead to an extended source in the coma. Over the last years, we have prepared the cometary rendezvous by the analysis of various samples with the reference model of COSIMA. We will report on this calibration data set and on the first results of the in-situ analysis of cometary grains as captured, imaged and analyzed by COSIMA.

References :

Bockelée-Morvan, D., et al. 2004. (Eds.), Comets II. the University of Arizona Press, Tucson, USA, pp. 391-423 ; Fomenkova, M.N., 1999. Space Science Reviews 90, 109-114 ; Kissel, J., Krueger, F.R., 1987. Nature 326, 755-760 ; Mitchell, et al. 1992. Icarus 98, 125-133 ; Mumma, M.J., Charnley, S.B., 2011. Annual Review of Astronomy and Astrophysics 49, 471-524.