日本地球惑星科学連合2018年大会

講演情報

[EE] 口頭発表

セッション記号 P (宇宙惑星科学) » P-PS 惑星科学

[P-PS03] 太陽系小天体研究:現状の理解と将来の展望

2018年5月24日(木) 13:45 〜 15:15 A02 (東京ベイ幕張ホール)

コンビーナ:石黒 正晃(ソウル大学物理天文学科)、中本 泰史(東京工業大学)、荒川 政彦(神戸大学大学院理学研究科、共同)、安部 正真(宇宙航空研究開発機構宇宙科学研究所)、座長:Ishiguro Masateru(Seoul National University)

14:00 〜 14:15

[PPS03-25] 「はやぶさ2」帰還試料分析に向けた、揮発性物質を含む地球外試料の多機関連携による非汚染総合分析手法の開発

*上椙 真之1伊藤 元雄2富岡 尚敬2大東 琢治3上杉 健太朗1唐牛 譲5白井 直樹6山口 亮4今栄 直也4矢田 達5安部 正真5 (1.公益財団法人 高輝度光科学研究センター、2.国立研究開発法人 海洋研究開発機構、3.大学共同利用機関法人 自然科学研究機構 分子科学研究所、4.大学共同利用機関法人 情報・システム研究機構 国立極地研究所、5.国立研究開発法人 宇宙航空研究開発機構、6.首都大学東京)

キーワード:はやぶさ2、帰還試料分析

In recent, we are able to obtain samples of extraterrestrial bodies, such as comets and asteroids, through direct sampling. Although the amount of those samples are not so large, and samples are less around 100 µm, we can obtain knowledges about origin and evolution of extraterrestrial bodies in solar system from many aspects, by applying the analytical methods developed for the analyses of meteorites and cosmic dusts. However, organic materials and water, those will be included in the samples obtained by future sample return missions, are easily damaged by the terrestrial contamination during analysis or sample preparations. In such cases, knowledges and experiences of analysis of extraterrestrial materials found on the surface of Earth will not be sufficient for the analysis of future analysis of returned samples. Special team for the analysis of organic particles inside the Hayabusa returned samples, called Category 3 particles, investigated the particles with several analytical methods along with the development of devices and methods for the analysis. Though they successfully reported results of their analysis, it took around 4 years after the return of the Hayabusa spacecraft.

On the bases of the experiences of such previous issues, we started the development of techniques and devices for the handling, transfer and analysis of samples returned by Hayabusa2 spacecraft from 2015, by organizing a special team constituting of members of Japan Aerospace Exploration Agency (JAXA), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Institute for Molecular Sciences (IMS), SPring-8 and National Institute of Polar Research (NIPR). Our activity includes development of sample container for distribution of samples with inter-facility transfer, atmosphere shielding sample holder, sample holder applicable for multiple analytical devices, and trial examinations of those developed devices through the analysis of extraterrestrial materials.

In this presentation, we report the results of sequential analysis of Antarctic micro-meteorites (AMMs) which simulated the small returned particles of Hayabusa2 returned samples, as the first step of a series of flow test. 10 Antarctic micrometeorites provided by NIPR were imaged by synchrotron radiation computed tomography (SR-CT) and x-ray diffraction (XRD) at SPring-8, and investigated by high resolution field emission scanning electron microscopy and energy dispersive spectroscopy (FE-SEM-EDS) system at IMS. Through the series of non-destructive analysis, we selected AMMs those having similar characteristics of carbonaceous chondrites, and formed thin sections by focused ion beam (FIB) for the characterization of organic materials by scanning transmitted x-ray microscopy and near edge x-ray absorption fine structure analysis (STXM-NEXAFS) at IMS, high resolution analysis by transmission electron microscopy (TEM), and isotopic analysis of light elements such as hydrogen, carbon, nitrogen and oxygen by secondary ion mass spectrometry (SIMS) at JAMSTEC.

We will also show the future plan of the developments and trial examinations. We will operate the rehearsals using mm-sized Antarctic meteorites simulating anlaysis of large particles of the Hayabusa2 returned samples, along with the development of sample fabrication methods and data sharing process of sequential analysis.