Current status and future plans of the preliminary
examination of Category 3 particles of Hayabusa-returnedsamples.
M. Uesugi1, H. Naraoka2, F. Kitajima2, M. Ito3, H. Yabuta4, Y.
Takano3, H. Mita5, K. Fukushima6, D. Aoki6, I. Ohnishi7, Y.
Kebukawa8, T. Yada1, Y. Karouji1, Y. Ishibashi1, T. Okada1 and
M. Abe1. 1JAXA/ISAS. 2Kyushu University. 3JAMSTEC. 4Osaka
University. 5Fukuoka Inst. Tech. 6Nagoya University. 7JEOL Ltd.
8
Hokkaido Univ.
E-mail: uesugi@plameta.sci.isas.jaxa.jp.
Introduction: Preliminary examinations of the carbonaceous
materials of Hayabusa-returned samples, Category 3, wasperformed in parellel with those of silicate materials by theHayabusa sample preliminary examination team (HASPET),
from early 2010. In the beginning of the examinations, weconsider that small pieces of viton gloves used in the cleanchamber 1 and 2 would be the most probable origin of category 3particles. However, as the number of category 3 particles
increased, we found variety of textures and chemicalcompositions of category 3 particles by FE-SEM observations.
The variation would indicate multiple origins of the carbonaceousmaterials. Consequently, we could not obtain any meaningful
data from the analysis during the first preliminary examinations.
The HASPET and Extraterrestrial sample curation team(ESCuTe) of JAXA restarted the examination with improving
sample handling methods and procedure for the sequential study.
In this paper, we summarize the result of the analysis obtained sofar, and discuss future plans for the determination of possible
origins of category 3 particles.
Procedure of the study and future plan: Samples allocatedfor the preliminary examinations of category 3 are RA-QD020008, RA-QD02-0120, RA-QD02-0180, RB-QD04-0001, RBQD04-0037-01 and RB-QD04-0047-02. RA-QD02-0008 was lost
during the manipulation at first preliminary examination. Threesamples, RA-QD02-0120, RB-QD04-0001, and RB-QD04-004702, were analyzed by the nano-SIMS, in order to investigate theisotopic anomaly which is the direct evidence of theextraterrestrial origin. All three particles, however, showed theterrestrial value of H, C and N isotopic ratio [1]. Because thesamples were flattened on the Au plate, we could obtain thespectra of FT-IR and micro-Raman spectroscopy with enoughsignal-to-noise ratio. In parallel with the Hayabusa-returned
particles, we processed observation and analysis of insolubleorganic matters (IOM) of A881458 (CM2) and several possible
materials for the origin of category 3, such as viton and vectran.
It seems that, however, the peak features of the category 3
particles were differ from all the spectra of those materials.
After those analysis, RA-QD02-0120 was sliced into ultrathin sections by FIB equipped to the Extraterrestrial sample
curation center, and in order to observe by TEM/STEM at JEOL.
ToF-SIMS analysis of RA-QD02-0180 and RB-QD04-0037-01
will be also performed after pressing on the indium plate prior to
the nano-SIMS analysis. Currently we prepared for thoseanalyses with determining the possible effect on the subsequent
analyses, such as sample damages and contaminations. The resultof the investigations will also be reported in other presentations[1-2] and subsequent papers in detail.
References: [1] Ito et al. 2013. Abstract of Hayabusa
Symposium, this issue [2] Uesugi et al. 2013. Abstract ofHayabusa Symposium, this issue.