insidethisissue - The Royal Astronomical Society of Canada

contains a high amount of organic carbon (~2.6 wt%) of which only 2%is soluble in polar solvents [1]. This study takes advantage of the pristinenature of the Tagish Lake meteorites collected a few days after theirfall [2] and that are available at the University of Alberta to 1) developa method for organic molecule analysis that can be readily applied inthe context of other (esp. mineralogical and petrological) studies, and2) identify sources of terrestrial contamination as part of efforts toestablish curation and handling protocols.Methods: A 1.685-g subsample of pristine Tagish Lake sample 11v(5.65 g of dust/disaggregated material in a Ziploc bag) forms the sourceof the material used in this study. The subsample was stored in an ArcontainingSchlenk vessel in a freezer at -30 °C. The extraction processinvolved adding ~0.40 mL of either neat dichloromethane (DCM) or a50:50 (v/v) toluene-methanol mixture to ~0.30 g of the dust at -78 °Cunder an Ar blanket. The resulting black slurry was allowed to warmto room temperature and lightly tapped, causing the insoluble materialto settle out. The slightly cloudy brown supernatant (~0.2 mL) wasextracted and split into two 0.1 mL portions, one of which was analyzedby GC-MS and the other by FTIR. GC-MS data were acquired with anAgilent Technologies 5975-C instrument equipped with an HP-5MScolumn packed with (5% phenyl)methyl polysiloxane. FTIR spectra wererecorded as DCM casts on a Thermo-Nicolet Nic Plan FTIR microscopeattached to a Magna 760 spectrometer. Omnic software (7.1) was usedto collect and process the spectra, which included 256 scans for bothbackground and sample over the range 4000-650 cm -1 .Results and Discussion: Through comparison of GC-MS resultswith known molecule retention times and peaks, we have identified 67organic molecules in the DCM extract, of which 10 are likely terrestrial.The organic molecules are linear and branched alkanes, aromatics,aldehydes, linear alkenes, carboxylic acids, and polyene, consistentwith [3]. Results of FTIR analysis show peaks from alkane C-H bondsbetween 2800 and 3000 cm -1 and aromatic C-H bonds at 3090 cm -1 ,consistent with results from GC-MS and [4]. The most prevalentterrestrial contaminant found is oleamide, a plasticizer used in themanufacture of Ziploc bags. Although it does not interfere significantlyin organic analysis of other molecules, Ziploc, and other plastic bags,are not optimal collection media.Conclusions: The soluble fraction of Tagish Lake organic carboncontains very few oxygenated groups. This is in contrast to themineralogy of Tagish Lake [5] and the insoluble organic matter, both ofwhich indicate low-temperature chemical oxidation on the parent body[6]. Determining the relationship between the petrology of Tagish Lakeand the distribution of organics is of primary importance in determiningthe origin and history of organic matter in the early Solar System.References:[1] Grady, M.M. et al. 2002, Meteor. Planet. Sci., 37, 713-735.[2] Hildebrand, A.R. et al. 2006, Meteor. Planet. Sci., 41, 407-431.[3] Pizzarello, S. et al. 2001, Science, 293, 2236-2239.[4] Matrajt, G. et al. 2004, Astronomy & Astrophysics, 416, 983-990.[5] Zolensky, M.E. et al. 2002, Meteor. Planet. Sci., 37, 737-761.[6] Cody, G.D. and Alexander, C.M.O.D. 2005, GCA, 69, 1085-1097.Astromaterials and Small Bodies Research at the University ofWinnipeg Planetary Spectrophotometer Facility. E.A. Cloutis,Department of Geography, University of Winnipeg, 515 Portage Ave,Winnipeg MB R3B 2E9 ( We have established a state-of-the-art spectrophotometerfacility at the University of Winnipeg tailored to supportingspectroscopy-based studies of planetary surfaces. The facility includesa variety of spectrophotometers spanning the range from the UV (200nm) to the far IR (200 m). The equipment suite includes benchtopspectrometers (Jasco Model 570 180-2500 nm; Buck M500: 2-16 µm; andHyperion/Bruker micro/macro FTIR: 0.3-200 µm). We also have fieldportableinstruments for studies of terrestrial analogues (Ocean OpticsS2000: 200-1150 nm; ASD FieldSpec HR: 350-2500 nm; D&P Model 102FTIR: 2-14 µm). Our lab currently supports a wide range of projects,including a number related to astromaterials and small bodies, and weare constantly upgrading our facilities and capabilities to better supportastromaterials research.Astromaterials Research: Our work on astromaterials to dategenerally falls into two broad categories: analysis of geological materialsin quarantine and direct analysis of astromaterials. We have developedenvironment chambers [1] that allow us to expose materials to variousplanetary surface conditions and monitor their spectral properties, aswell as to measure spectra of materials in quarantine. This capabilityis currently being used to determine mineral stabilities on the Martiansurface [2]. We are currently studying the spectral properties of ironmeteorites as a guide to analysis of M-asteroid spectra. We havealso measured reflectance spectra of thermally processed ordinarychondrites to support analysis of S-asteroid reflectance spectra. We arealso developing a capability to spectrally characterize single-mineralgrains.Small-bodies research: Our research on small bodies is currentlyfocused on asteroids, comets, and terrestrial analogues. We are in themidst of an extensive study of the spectral reflectance properties ofpossible S-class asteroid surface assemblages: iron-meteorite-silicatemixtures, olivine-pyroxene, and two pyroxene-mixtures. These dataare being used by colleagues at the University of North Dakota in theinterpretation of M- and S-class asteroid spectra [3].Other asteroid-related projects currently under way includeanalysis of a small absorption band in pyroxenes at 506 nm that hasbeen detected in telescopic spectra of Vesta, and that shows rotationalvariations in wavelength position and depth, which may be a sensitiveindicator of pyroxene composition [4]. We are also examining spectralproperties of shocked materials from the Mistastin and St. Martincraters to determine how shock processes may affect spectral propertiesof planetary surfaces.The U of W is also engaged in a feasibility study with colleaguesfrom Europe on a proposed ESA comet sample-return mission; our roleis to assess the applicability of reflectance spectroscopy for surfacecharacterization.References:[1] Cloutis, E., Craig, M., Kaletzke, L., McCormack, K., and Stewart, L.2006, Lunar Planet. Sci., 37, abstr. #2121.[2] Cloutis, E.A., Craig, M.A., Mustard, J.F., Kruzelecky, R.V., Jamroz,W.R., Scott, A., Bish, D.L., Poulet, F., Bibring, J., and King, P.L. 2007,Geophys. Res. Lett., 34, L20202, doi:10.1029/2007GL031267.[3] Hardersen, P.S., Gaffey, M.J., Cloutis, E.A., Abell, P.A., and Reddy, V.2006, Icarus, 181, 94-106.[4] Kaletzke, L., Cloutis, E., Craig, M., McCormack, K., and Stewart, L.2006, Lunar Planet. Sci., 37, abstr. #2174.Sponsored by: Canadian Space Agency, UWO Planetary Science Research Group, and Geophysics Division of the Geological Associationof Canada58 Building for the International Year of Astronomy (IYA2009)JRASC April / avril 2008

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