専門・基盤技術グループ
Profile Information
- Affiliation
- Professor, Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency
- Degree
- Ph.D.(Mar, 2005, The University of Tokyo)
- J-GLOBAL ID
- 200901090793977023
- researchmap Member ID
- 5000092383
Research Interests
5Research History
4-
Feb, 2007 - Jun, 2009
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Apr, 2005 - Jan, 2007
Education
3-
Apr, 1996 - Mar, 1998
Committee Memberships
5-
Apr, 2023 - Present
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May, 2021 - Apr, 2023
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May, 2016 - Jul, 2017
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Nov, 2015 - Jul, 2017
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Oct, 2013 - Jul, 2015
Awards
25-
Apr, 2023
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Nov, 2021
Papers
250-
Acta Astronautica, Dec, 2025
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Acta Astronautica, Oct, 2025 Peer-reviewedLead authorCorresponding author
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Science Advances, 10(39), Sep 27, 2024The isotopic compositions of samples returned from Cb-type asteroid Ryugu and Ivuna-type (CI) chondrites are distinct from other carbonaceous chondrites, which has led to the suggestion that Ryugu/CI chondrites formed in a different region of the accretion disk, possibly around the orbits of Uranus and Neptune. We show that, like for Fe, Ryugu and CI chondrites also have indistinguishable Ni isotope anomalies, which differ from those of other carbonaceous chondrites. We propose that this unique Fe and Ni isotopic composition reflects different accretion efficiencies of small FeNi metal grains among the carbonaceous chondrite parent bodies. The CI chondrites incorporated these grains more efficiently, possibly because they formed at the end of the disk’s lifetime, when planetesimal formation was also triggered by photoevaporation of the disk. Isotopic variations among carbonaceous chondrites may thus reflect fractionation of distinct dust components from a common reservoir, implying CI chondrites/Ryugu may have formed in the same region of the accretion disk as other carbonaceous chondrites.
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Nature Communications, 15 7488, Aug 29, 2024 Peer-reviewedAbstract Primordial carbon delivered to the early earth by asteroids and meteorites provided a diverse source of extraterrestrial organics from pre-existing simple organic compounds, complex solar-irradiated macromolecules, and macromolecules from extended hydrothermal processing. Surface regolith collected by the Hayabusa2 spacecraft from the carbon-rich asteroid 162173 Ryugu present a unique opportunity to untangle the sources and processing history of carbonaceous matter. Here we show carbonaceous grains in Ryugu can be classified into three main populations defined by spectral shape: Highly aromatic (HA), Alkyl-Aromatic (AA), and IOM-like (IL). These carbon populations may be related to primordial chemistry, since C and N isotopic compositions vary between the three groups. Diffuse carbon is occasionally dominated by molecular carbonate preferentially associated with coarse-grained phyllosilicate minerals. Compared to related carbonaceous meteorites, the greater diversity of organic functional chemistry in Ryugu indicate the pristine condition of these asteroid samples.
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Space Telescopes and Instrumentation 2024: Optical, Infrared, and Millimeter Wave, 213-213, Aug 23, 2024
Misc.
210-
A Study on Estimation of Thruster Errors Using Disturbance Observer in Deep Space Rendezvous DockingThe 34th Workshop on JAXA Astrodynamics Symposium and Flight Mechanics, Jul, 2024
Books and Other Publications
2Presentations
2Professional Memberships
1-
Apr, 2005 - Present
Research Projects
7-
科学研究費助成事業, 日本学術振興会, Apr, 2024 - Mar, 2028
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Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (A), Japan Society for the Promotion of Science, Apr, 2019 - Mar, 2024
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Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (C), Japan Society for the Promotion of Science, Apr, 2018 - Mar, 2021
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Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Japan Society for the Promotion of Science, Apr, 2016 - Mar, 2019
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Grants-in-Aid for Scientific Research Grant-in-Aid for Scientific Research (B), Japan Society for the Promotion of Science, Apr, 2014 - Mar, 2018