PRELIMINARY EXAMINATION OF CARBONACEOUS
MATERIALS
OFTHE
HAYABUSA-RETURNEDSAMPLES.
M. Uesugi1, H. Naraoka2, F. Kitajima2, M. Ito3, H. Yabuta4, Y.
Takano3, H. Mita5, T. Yada1, Y. Karouji1, Y. Ishibashi1, T.
Okada1 and M. Abe1. 1JAXA/ISAS. 2Kyushu University.
3
JAMSTEC. 4Osaka University. 5Fukuoka Inst. Tech.
E-mail: uesugi@plameta.sci.isas.jaxa.jp.
Introduction: Extraterrestrial Sample Curation Team(ESCuTe) recovered more than 400 particles from the sample
catcher of the Hayabusa, after the returning of the spacecraft tothe Earth [1]. Most of the particles were silicate materials, mainlycomposed of olivine, pyroxene, plagioclase and iron-sulfide.
Through the preliminary examinations, it was confirmed thatthese silicate materials were actually extraterrestrial origin, andequivalent to the high petrologic type of LL chondrite [2-7]. In
addition to these silicate particles, some amount of carbonaceous
materials were also found. Those carbonaceous materials, named
as category 3, were found in the form of particles with similar
size range of the silicates. More than 50 particles out of therecovered particles were recognized as category 3. Initialdescription by the SEM-EDS analysis shows variable texturesand chemical compositions of them, suggesting the multiple
origins of the carbonaceous materials.
Preliminary examinations of category 3 particles were
carefully processed in parallel with those of silicate materials.
However, we could not obtain the information for the origin of
category 3 particles before the opening of international
announcement of opportunity (A/O). The ESCuTe andpreliminary examination team of category 3 particles havecontinued their investigations, and recently we could obtainseveral results of our continuous analysis.
In this paper, we introduce the preliminary examination ofcategory 3 particles with the concept of the sequential studies.
Procedure of the study and future plan: Three samples
were analyzed so far. The samples were pressed on the Au plateand fixed without any adhesive materials. We analyzed H, C andN isotopic composition by nano-SIMS in the beginning of thesequential study, in order to investigate the isotopic anomaly
which is a direct evidence of extraterrestrial origin of organic
materials. FT-IR and micro-Raman spectroscopy were also
applied for the pressed samples, and then the samples were sliced
by FIB in order to investigate the fine structure of the samples by
XANES and TEM/STEM. We did not obtained any signature foran extraterrestrial origin from category 3 particles so far. Detailsof those analyses and results will be also presented by several
authors [8, 9].
We are planning to continue the preliminary examination ofcategory 3 by the end of March 2014. We are also planning toopen the category 3 particles to the future International A/O, withthe data of preliminary examinations before the end of 2014.
References: [1] Yada et al. 2011. Meteoritics & Planetary
Science 32:A74. [2] Nakamura et al. 2011. Science 333:11131116. [3] Yurimoto et al. 2011. Science 333:1116-1119. [4]Ebihara et al. 2011. Science 333:1119-1121. [5] Noguchi et al.
(2011) Science 333:1121-1125. [6] Tsuchiyama et al. 2011.
Science 333:1125-1128. [7] Nagao et al. 2011. Science 333:11281131. [8] Ito et al. 2013. Abstract of Hayabusa Symposium thisissue [9] Uesugi et al. 2013. Abstract of Hayabusa Symposium
this issue.