研究者業績
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 (工学)(2021年 名古屋大学)
- 研究者番号
- 20944549
- ORCID ID
https://orcid.org/0000-0002-3094-6716- J-GLOBAL ID
- 202201010645145808
- researchmap会員ID
- R000032549
研究キーワード
6経歴
6-
2024年10月 - 現在
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2021年10月 - 2024年9月
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2022年10月 - 2023年3月
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2020年4月 - 2021年9月
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2018年9月 - 2020年3月
学歴
3-
2018年10月 - 2021年9月
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2013年4月 - 2015年3月
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2009年4月 - 2013年3月
受賞
6-
2021年10月
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2021年6月
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2021年3月
論文
15-
Nature Communications 2026年3月17日 査読有り
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Acta Astronautica 240 888-892 2026年3月 査読有り
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Journal of Geophysical Research: Planets 130(10) 2025年10月9日 査読有りAbstract The successful sample return from asteroid (162173) Ryugu by Hayabusa2 has contributed to our understanding of the solar system evolution. Over the course of the initial sample analysis, various measurements were conducted, such as mineralogical observation, chemical analysis, and mechanical property measurement. These pieces of information allow us to give constraints on the essential conditions of Ryugu's formation and evolution processes (e.g., thermal environment, aqueous alteration, formation of a rubble‐pile body), leading to a clearer view of the early solar system. Here, we report the initial results of the elastic properties of Ryugu particles (e.g., P‐ and S‐wave velocities and Young's modulus) obtained via ultrasonic pulse transmission measurement. Our measurement results showed 2.15 0.05 km/s and 1.25 0.05 km/s for the compressional and shear waves, respectively. Regarding Young's modulus, we obtained 7.1 0.6 GPa, consistent with the previously measured value via a nanoindentation test. Compared with the elastic properties of other carbonaceous chondrites (Tagish Lake, Tarda, Ivuna, and Murchison meteorites), we found that Ryugu had distinctly lower rigidity than Ivuna—the most similar material to Ryugu with respect to chemical and mineralogical features. Instead, Tagish Lake showed the closest elastic properties to Ryugu samples. The affinities in chemical and mineralogical features indicate the genetic relationship between Ryugu and Ivuna. On the other hand, the difference in elastic properties might indicate their formation and evolution processes proceeded differently (e.g., formation depth, degree of alteration).
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International Journal of Thermophysics 46(10) 2025年7月28日 査読有りAbstract The regolith on the shallow lunar surface was formed through micrometeorite impacts over time. Investigating the thermophysical properties of the regolith provides valuable insights into the thermal history of the Moon as recorded by these surface materials and offers critical data for future lunar exploration. In several studies, the thermophysical properties of the regolith layer and rocks have been examined, but few studies have focused on individual regolith particles because of their limited size and irregular shapes, which are generally believed to have formed following intense activities, such as micrometeorite impacts. In this study, the local thermal diffusivity of individual particles from Apollo 17 sample 70161 was measured via the lock-in thermography (LIT) technique, and subsequently, the distribution of in-plane thermal diffusivity was provided. The particle was confirmed to be a typical breccia using X-ray tomography (XCT) assisted by X-ray diffraction (XRD). The local average thermal diffusivity values ranged from 2.9 m 2 ·s −1 to 3.6 × 10 −7 m 2 ·s −1 and showed an anisotropic distribution. In addition, we calculated the representative thermal conductivity and thermal inertia of the particles via the specific heat and density, which are 0.738 ± 0.088 W.m −1 ·K −1 (300 K) and (1.231 ± 0.086) × 10 3 J·m −2 ·s −1/2 ·K −1 (300 K), respectively. The specific heat was also obtained by differential scanning calorimetry (DSC) of fine samples from 70161. The density was calculated from the measured weight, and the volume was determined via XCT. On the one hand, our experimental results are in good agreement with previously reported measurements of Apollo lunar rocks (in terms of average values). On the other hand, our measurements also reveal an anisotropic distribution of thermal diffusivity within localized regions of the particle. This anisotropy is attributed to factors such as cracks and defects, which locally weaken heat conduction.
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International Journal of Thermophysics 46(4) 2025年2月25日 査読有り
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Netsu Bussei 37(4) 127-136 2023年11月 査読有り筆頭著者
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International Journal of Thermal Sciences 193 108475-108475 2023年11月 査読有り筆頭著者
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Science 379(6634) 2023年2月24日 査読有りSamples of the carbonaceous asteroid Ryugu were brought to Earth by the Hayabusa2 spacecraft. We analyzed 17 Ryugu samples measuring 1 to 8 millimeters. Carbon dioxide–bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu’s parent asteroid formed in the outer Solar System. The samples contain low abundances of materials that formed at high temperatures, such as chondrules and calcium- and aluminum-rich inclusions. The samples are rich in phyllosilicates and carbonates, which formed through aqueous alteration reactions at low temperature, high pH, and water/rock ratios of <1 (by mass). Less altered fragments contain olivine, pyroxene, amorphous silicates, calcite, and phosphide. Numerical simulations, based on the mineralogical and physical properties of the samples, indicate that Ryugu’s parent body formed ~2 million years after the beginning of Solar System formation.
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International Journal of Thermophysics 44(4) 2023年2月9日 査読有り筆頭著者
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International Journal of Thermophysics 43(7) 2022年5月3日 査読有り筆頭著者
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Review of Scientific Instruments 91(6) 064901-064901 2020年6月1日 査読有り筆頭著者
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Infrared Physics & Technology 99 248-256 2019年6月 査読有り筆頭著者
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International Journal of Thermophysics 36(10-11) 2577-2589 2014年10月7日 査読有り筆頭著者
MISC
11講演・口頭発表等
31-
Japan Geoscience Union (JpGU) Meeting 2024 2024年5月
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Sample Analysis Team Meeting (SATM)-4 2024年4月
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Hayabusa 2023 Symposium 2023年11月15日
担当経験のある科目(授業)
1-
2022年10月 - 2023年3月物理学実験（生） (立教大学)
所属学協会
3共同研究・競争的資金等の研究課題
2-
日本学術振興会 科学研究費助成事業 2024年4月 - 2027年3月
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日本学術振興会 科学研究費助成事業 2020年4月 - 2022年3月
