MMX Project Team

深井 稜汰

フカイ リョウタ  (Ryota Fukai)

基本情報

所属
国立研究開発法人宇宙航空研究開発機構 宇宙科学研究所 太陽系科学研究系 特任助教
学位
博士(理学)(2019年3月 東京工業大学)

連絡先
fukai.ryohtajaxa.jp
研究者番号
10848469
ORCID ID
 https://orcid.org/0000-0002-1477-829X
J-GLOBAL ID
201901013277717727
Researcher ID
I-1911-2016
researchmap会員ID
B000354117

外部リンク

主要な論文

 38
  • Ryota Fukai, Tomohiro Usui, Wataru Fujiya, Yoshinori Takano, Ken‐ichi Bajo, Andrew Beck, Enrica Bonato, Nancy L. Chabot, Yoshihiro Furukawa, Hidenori Genda, Yuki Hibiya, Fred Jourdan, Thorsten Kleine, Mizuho Koike, Moe Matsuoka, Yayoi N. Miura, Frédéric Moynier, Ryuji Okazaki, Sara S. Russell, Hirochika Sumino, Michael E. Zolensky, Haruna Sugahara, Shogo Tachibana, Kanako Sakamoto, Masanao Abe, Yuichiro Cho, Kiyoshi Kuramoto
    Meteoritics and Planetary Science 2024年1月11日  査読有り筆頭著者責任著者
    Abstract Japan Aerospace Exploration Agency's Martian Moons eXploration (MMX) mission will launch a spacecraft in 2024 to return samples from Phobos in 2029. Curatorial work for the returned Phobos samples is critical for the sample allocation without degrading the sample integrity and subsequent sample analysis that will provide new constraints on the origin of Phobos and the evolution of the circum‐Mars environment. The Sample Analysis Working Team of the MMX is designing the sample curation protocol. The curation protocol consists of three phases: (1) quick analysis (extraction and mass spectrometry for gases), (2) pre‐basic characterization (bulk‐scale observation), and (3) basic characterization (grain‐by‐grain observation and allocation of the sample aliquots). Nondestructive analyses within the clean chamber (e.g., visible and near‐infrared spectral imaging) and outside the chamber (e.g., gas mass spectrometry) are incorporated into the curation flow in coordination with the MMX mission instrument teams for ground‐truthing the remote‐sensing data sets. The MMX curation/sample analysis flow enables the seamless integration between the sample and remote‐sensing data sets to maximize the scientific value of the collected Phobos samples.
  • Sota Arakawa, Ryota Fukai, Kazuaki Homma
    Yuseijin 31(1) 50-67 2022年3月25日  査読有り招待有り
  • Ryota Fukai, Sota Arakawa
    The Astrophysical Journal 908(1) 64-64 2021年2月15日  査読有り筆頭著者責任著者
  • Ryota Fukai, Tetsuya Yokoyama
    EARTH AND PLANETARY SCIENCE LETTERS 474 206-214 2017年9月  査読有り筆頭著者責任著者
    We present high-precision Nd isotope compositions for ordinary and carbonaceous chondrites determined using thermal ionization mass spectrometry with dynamic and multistatic methods. The ordinary chondrites had uniform and non-terrestrial mu Nd-142, mu Nd-148, and mu Nd-150 values, with data that plot along the mixing line between s-process and terrestrial components in mu Nd-150 versus mu Nd-148 and mu Nd-142 versus mu Nd-148,Nd-150 diagrams. In contrast, the carbonaceous chondrites were characterized by larger anomalies in their mu Nd-142, mu Nd-148, and mu Nd-150 values compared to ordinary chondrites. Importantly, the data for carbonaceous chondrites plot along the s-process and terrestrial mixing line in a mu Nd-150 versus mu Nd-148 diagram, whereas they have systematically lower mu Nd-142 values than the s-process and terrestrial mixing line in mu Nd-142 versus mu Nd-148,Nd-150 diagrams. This shift likely results from the incorporation of calcium- and aluminum-rich inclusions (CAIs), indicating that the Nd isotopic variability in the ordinary chondrites and CAI-free carbonaceous chondrites was caused solely by the heterogeneous distribution of s-process nuclides. The isotopic variation most likely results from nebular thermal processing that caused selective destruction of s-process-depleted (or r-process-enriched) dust grains in the inner Solar System where the parent bodies of ordinary chondrites formed, whereas such grains were preserved in the region of carbonaceous chondrite parent body formation. The Nd isotope dichotomy between ordinary and bulk aliquots of carbonaceous chondrites can be related to the presence of Jupiter, which may have separated two isotopically distinct reservoirs that were present in the solar nebula. After correcting for s-process anomalies and CAI contributions to the Nd isotopes observed in the chondrites, we obtained a mu Nd-142 value (-2.4 +/- 4.8 ppm) that was indistinguishable from the terrestrial value. Our results corroborate the interpretation that a missing reservoir (e.g., a hidden enriched reservoir, erosional loss of crust) is not required to explain the observed differences in Nd-142/Nd-144 ratios between chondrites and terrestrial materials. (C) 2017 Elsevier B.V. All rights reserved.

MISC

 13

主要な講演・口頭発表等

 40

担当経験のある科目(授業)

 2

所属学協会

 6

Works(作品等)

 1

主要な共同研究・競争的資金等の研究課題

 13

学術貢献活動

 17

社会貢献活動

 22

メディア報道

 2

その他

 2