Personal Information｜


兵頭龍樹

Dr. Ryuki Hyodo / 兵頭龍樹, Ph.D. (2016)
  • Tokyo University of Science (formerly Tokyo Institute of Technology) / 東京科学大学（旧・東京工業大学）
  • Université Paris Cité, Institut de Physique du Globe de Paris (IPGP) / パリ・シテ大学, 地球物理研究所
  • Rikkyo University, Graduate School of Artificial Intelligence and Science, Visiting Associate Professor
  • SpaceDATA Inc. Chief Science Officer (CSO)
  • Galaxies, Inc. Adviser
Email: hyodo@elsi.jp
My latest curriculum vitae (CV) is available HERE (updated 2021/3/30)

Awards｜

  • 2023 「S-Booster 最優秀賞」「S-Booster NEDO賞」 S-Booster 2023
  • 2023 「立教大学教育活動特別賞」 Rikkyo University
  • 2022 「JAXA理事長賞」「President Award」 JAXA
  • 2022 「最優秀研究者賞」「Outstanding Young Scientist Award」 The Japanese Society for Planetary Sciences (JSPS)
  • 2019 「JAXA理事長賞」「President Award」 JAXA
  • 2017 「学長賞」「The President Award」 Kobe University
  • 2016 「最優秀発表賞」「Best Research Presentation Award」 The Japanese Society for Planetary Sciences (JSPS)
  • 2016 「学長賞」「The President Award」 Kobe University

Grants｜

  • FY2024-FY2025 国際共同研究加速基金（国際共同研究強化）
    「進化する原始惑星系円盤における微惑星形成の理論研究：内惑星領域から外惑星領域まで」
    12,000,000 JPY (PI)
  • FY2022-FY2025 科学研究費補助金 若手研究
    「進化する原始惑星系円盤における微惑星形成の理論研究」
    3,600,000 JPY (PI)
  • FY2021-FY2025 科学研究費補助金 基盤A
    「岩石・氷・ガス惑星の衛星形成の総合的モデル:太陽系、系外惑星系」
    32,100,000 JPY (Co-PI)
  • FY2021-FY2025 科学研究費補助金 基盤A
    「火星衛星の形成過程を解明する」
    32,100,000 JPY (Co-PI)
  • FY2020-FY2025 国際共同研究加速基金（国際共同研究強化B）
    「火星衛星の形成過程を解明する」
    18,720,000 JPY (Co-PI)
  • FY2019-FY2024 JAXA ITYF Program Incentives
    「火星衛星サンプルリターンおよび土星衛星環サンプルリターン計画への太陽系形成理論モデルからの検討」
    12,500,000 JPY (PI)
  • FY2018-FY2021 科学研究費補助金 若手研究
    「多様な地球型惑星が持つ衛星系の起源・進化の統一的理解に向けた理論研究」
    4,160,000 JPY (PI)
  • FY2017-FY2018 学振(二国間交流事業)・SAKURAプログラム
    「地球型惑星における巨大天体衝突と衛星形成過程の解明」
    1,900,000 JPY (Co-PI)
  • FY2017-FY2017 NINS・ABC Project / NINS・ABCプロジェクト
    「巨大天体衝突による連惑星形成の可能性について」
    2,100,000 JPY (Co-PI)
  • FY2017-FY2019 JSPS Research Fellow / 特別研究員奨励費 (PD)
    「多様なリング-衛星系の起源・進化の統一的理解に向けた理論研究」
    4,810,000 JPY (PI)
  • FY2015-FY2016 JSPS Research Fellow / 特別研究員奨励費 (DC2)
    「惑星が持つ衛星-リング系の多様性:その起源と進化の理論的研究」
    1,900,000 JPY (PI)

Lectures｜

  • International Space University
    • Space Studies Program 2023 (SSP23), "Our Solar System and Exoplanets"
    • Space Studies Program 2023 (SSP23), "Moon & Mars"
  • Rikkyo University (立教大学) 「全学共通科目(全カリ)・地球の理解」
    • 2020年度前期
    • 2021年度前期
    • 2022年度前期
    • 2023年度前期
  • Rikkyo University (立教大学) 「人工知能社会実装」
    • 2025年度前期

Refereed Publications｜

52 publications (25 as the first author)
8 publications in Nature / Science publishing group (4 as the first author)

  1. Hyodo R. and Torii N. (2026). "Dynamical Evolution of V-Shaped Collision Debris". Submitted
  2. Hyodo R., Wakita S., Johnson B.C. (2026). "Numerical Simulations of Hypervelocity Micrometeoroid Impacts: Rocky Impactors onto Icy Targets and the Role of Porosity". Submitted
  3. Ochiai Y., Hyodo, R., Ida S., Shoji D. (2026). "Chemical Evolution of Vapor Plumes Produced by Micrometeoroid Impacts on Saturn's Rings: Insights into the CO- and Organics-Rich Equatorial Inflow from the Rings". Icarus submitted
  4. Torii N., Ida S., Hyodo, R. (2026). "Ring formation around giant planets by tidal disruption of a single passing large Keiper belt object II: The dynamical fate of tidal fragments". Icarus submitted
  5. Kitazato K., Sakurai S., Hyodo, R., Hirata N. (2025). "Surface rejuvenation of near-Earth asteroids triggered by planetary shadows". Nature Geoscience
    Nature Geoscience
  6. Hyodo R. and Ida S. (2025). "Ringed vs. Ringless Worlds: How Poynting-Robertson Drag Shapes Rings Across the Solar System". Astrophysical Journal Letters 994 L15
    arXiv:2510.25302 ApJL 994 L15
  7. Barucci M.A., Bernardi P., Reess J-M., et al. (inc.Hyodo, R.) (2025). "The MMX InfraRed Spectrometer (MIRS) for spectral characterization of Mars system". Earth, Planets and Space 12, 69
    Earth, Planets and Space 12, 69
  8. Allibert L., Siebert J., Hyodo R., Genda H., Raymond S., Jacobson S., Nakajima M., Charnoz S. (2025). "Collisional erosion of mantle silicate during accretion can set the elevated Fe/Mg ratio of Earth". Icarus 429, 15
    Icarus 429, 15
  9. Hyodo R., Genda H., Madeira G. (2025). "Pollution resistance of Saturn's ring particles during micrometeoroid impact". Nature Geoscience 18, 44-49
    Nature Geoscience 18, 44-49
  10. Hirata K., Usui T., Hyodo R. et al. (2024). "Mixing model of Phobos' bulk elemental composition for the determination of its origin: Multivariate analysis of MMX/MEGANE data". Icarus 410, 115891
    arXiv:2311.15676 Icarus 410, 115891
  11. Madeira G., Charnoz S., Zhang Y., Hyodo R., Michel P., Genda H., Winter S.G. (2023). "Exploring the recycling model of Phobos formation: rubble-pile satellites". AJ 165, 161
    arXiv:2302.12556 AJ 165 161
  12. Madeira G., Charnoz S. & Hyodo R. (2023). "Dynamical origin of Dimorphos from fast spinning Didymos". Icarus 394, 115428
    arXiv:2301.02121 Icarus 394, 115428
  13. Okuya A., Ida S., Hyodo R., & Okuzumi S. (2023). "Modelling the evolution of silicate/volatile accretion discs around white dwarfs". MNRAS 519, 1657
    arXiv:2211.16797 MNRAS 519, 1657
  14. Liang Y. & Hyodo R. (2023). "Giga-year dynamical evolution of particles around Mars". Icarus 391, 115335
    arXiv:2211.00220 Icarus, 391, 115335
  15. Hyodo R. and Sugiura, K. (2022). "Formation of moons and equatorial ridge around top-shaped asteroids after surface landslide". ApJL, 937, L36
    arXiv:2209.07045 ApJL, 937, L36
  16. Nakamura T., Matsumoto M., Amano K., et al. (inc.Hyodo, R.) (2022). "Formation and evolution of Cb-type asteroid Ryugu: Direct evidence from returned samples". Science 379, eabn8671
    Science 379, eabn8671
  17. Hyodo R., Genda H., Sekiguchi R., Madeira G., Charnoz S. (2022). "Challenges in forming Phobos and Deimos directly from a splitting of an ancestral single moon". Planet. Sci. J. 3, 204
    arXiv:2208.04794 PSJ, 3, 204
  18. Ozaki N., Yanagida K., Chikazawa T., Takeishi N. & Hyodo R. (2022). "Asteroid Flyby Cycler Trajectory Design Using Deep Neural Networks". JGCD, 0 0:0, 1-16
    arXiv:2111.11858 JGCD, 0 0:0, 1-16
  19. Hyodo R., Ida S., Guillot T. (2022). "A 'no-drift' runaway pile-up of pebbles in protoplanetary disks II. Characteristics of the resulting planetesimal belt". A&A, 660, A117
    arXiv:2202.04143 A&A, 660, A117
  20. Barucci M.A., Reess J.M., Bernardi P., et al. (inc.Hyodo, R.) (2021). "MIRS: an imaging spectrometer for the MMX mission". Earth, Planets and Space, 73, 211
    Earth, Planets and Space, 73, 211
  21. Hyodo R. & Usui T. (2021). "Searching for life in Mars and its moons". Science 373, 742
    Science 373, 742
  22. Arakawa S., Hyodo R., Shoji D. & Genda H. (2021). "Tidal evolution of the eccentric moon around dwarf planet (225088) Gonggong". AJ, 162, 226
    arXiv:2108.08553 AJ 162 226
  23. Hyodo R. & Genda H. (2021). "Erosion and accretion by cratering impacts on rocky and icy bodies". ApJ, 913, 77
    arXiv:2104.04981 ApJ, 913, 77
  24. Charnoz S., Avice G., Hyodo R., Pignatale F.C., & Chaussidon M. (2021). "Forming pressure-traps at the snow-line to isolate isotopic reservoirs in the absence of a planet". A&A, 652, A35
    arXiv:2105.00456 A&A, 652, A35
  25. Sugiura K., Kobayashi H., Watanabe S., Genda, H., Hyodo R. & Inutsuka S. (2021). "SPH simulations for shape deformation of rubble-Pile asteroids through spinup: the challenge for making top-shaped asteroids Ryugu and Benue". Icarus, 365, 114505
    arXiv:2104.13516 Icarus, 365, 114505
  26. Charnoz S., Sossi A.P., Lee YN., Siebert J., Hyodo R., Allibert L., Pignatale FC., Landeau M., Oza A.V. & Moynier F. (2021). "Tidal pull of the Earth strips the proto-Moon of its volatiles". Icarus, 364, 114451
    arXiv:2105.00917 Icarus, 364, 114451
  27. Hyodo R., Ida S., Guillot T. (2021). "A 'no-drift' runaway pile-up of pebbles in protoplanetary disks in which midplane turbulence increases with radius". A&A, 645, L9
    arXiv:2012.12511 A&A, 645, L9
  28. Hyodo R., Guillot T., Ida S., Okuzumi S. and Youdin A. (2021). "Planetesimal formation around the snow line. II. Dust or pebbles?". A&A, 646, A14
    arXiv:2012.06700 A&A, 646, A14
  29. Ida S., Guillot T., Hyodo R., Okuzumi S. and Youdin A. (2021). "Planetesimal formation around the snow line. I. Monte Carlo simulations of silicate dust pile-up in a turbulent disk". A&A, 646, A13
    arXiv:2011.13164 A&A, 646, A13
  30. Hyodo, R., Genda, H. & Brasser, R. (2021). "Modification of the composition and density of Mercury from late accretion". Icarus, 354, 114064
    arXiv:2008.08490 Icarus
  31. Hyodo, R. & Genda, H. (2020). "Escape and accretion by cratering impacts: Formulation of scaling relations for high-speed ejecta". ApJ, 898, 30
    arXiv:2006.00732 ApJ, 898, 30
  32. Rothery D., Massironi M., Alemanno G., et al. (inc.Hyodo, R.) (2020). "Rationale for BepiColombo Studies of Mercury's Surface and Composition". Space Science Reviews 216, 66
    Space Science Reviews 216, 66
  33. Rosenblatt P., Hyodo R., Pignatale F., Charnoz S., Trinh A., Dunseath-Terao M., Dunseath K.M., Genda H. (2020). "The formation of the Martian moons", Oxford Science Encyclopedia
    arXiv:1909.03996 Oxford Science Encyclopedia
  34. Hyodo, R., Kurosawa, K., Genda, H., Usui, T. & Fujita, K. (2019). "Transport of impact ejecta from Mars to its moons as a means to reveal Martian history", Scientific Reports 9, 19833
    arXiv:1912.12056 Scientifc Reports 9, 19833
  35. Fujita, K., Kurosawa, K., Genda, H., Hyodo, R., Matsuyama, S., Yamagishi, A., Mikouchi, T., and Niihara, T. (2019). "Assessment of microbial contamination probability for sample return from martian moons I: The departure of the microbes from Martian surface". Life Sciences in Space Research 23, 73-84
    arXiv:1907.07575 Life Sciences in Space Research 23, 73-84
  36. Hyodo, R., Ida, S., Charnoz, S. (2019). "Formation of rocky and icy planetesimals inside and outside the snow lin: Effects of diffusion, sublimation and back-reaction". A&A, A90, 13
    arXiv:1907.04621 A&A, A90, 13
  37. Kurosawa, K., Genda, H., Hyodo, R., Yamagishi, A., Mikouchi, T., Niihara, T., Matsuyama, S. and Fujita, K. (2019). "Assessment of the probability of microbial contamination for sample return from Martian moons II: The fate of microbes on Martian moons". Life Sciences in Space Research 23, 85-100
    arXiv:1907.07576 Life Sciences in Space Research 23, 85-100
  38. Arakawa, S., Hyodo, R., Genda, H. (2019). "Early formation of moons around large trans Neptunian objects via giant impact". Nature Astronomy, 3, 802-807
    arXiv:1906.10833 Nature Astronomy, 3, 802-807
  39. Charnoz, S., Pignatale, F., Hyodo, R., Mahan, B., Chaussidon, M., Siebert, J., Moynier, M. (2019). "Planetesimal formation in an evolving protoplanetary disk with a dead zone". A&A 627, A50
    A&A, 627, A50
  40. Hyodo, R., Genda, H., Charnoz, S., Pignatale, F., Rosenblatt, P. (2018). "On the Impact Origin of Phobos and Deimos. IV. Volatile depletion". ApJ, 860, 150
    arXiv:1804.08889 ApJ, 860, 150
  41. Hyodo, R. & Genda, H. (2018). "Implantation of Martian materials in the inner solar system by a mega impact on Mars". ApJL 856, 2
    arXiv:1803.07196 ApJL, 856, 2
  42. Charnoz, S., Crida, A., Hyodo, R. (2018). "Rings in the Solar System: a short review". Handbook of Exoplanets
    arXiv:1805.08963 Handbook of Exoplanets
  43. Pignatale, F., Charnoz, S., Rosenblatt, P., Hyodo, R., Nakamura, T., Genda, H. (2018). "On the Impact Origin of Phobos and Deimos. III. resulting composition from different impactors". ApJ, 853, 118
    arXiv:1712.05154 ApJ, 853, 2
  44. Hyodo, R., Rosenblatt, P., Genda, H., Charnoz, S., (2017). "On the Impact Origin of Phobos and Deimos. II. True polar wander and disk evolution". ApJ 851, 122
    arXiv:1711.02334 ApJ, 851 122
  45. Hyodo, R., Genda, H., Charnoz, S., & Rosenblatt, P., (2017). "On the Impact Origin of Phobos and Deimos. I. Thermodynamic and Physical Aspects". ApJ, 845, 125
    arXiv:1707.06282 ApJ, 845, 125
  46. Hyodo, R. & Charnoz, S. (2017). "Dynamical Evolution of the Debris Disk after a Satellite Catastrophic Disruption around Saturn". AJ, 154, 34
    arXiv:1705.07554 AJ, 154, 34
  47. Hyodo, R., Charnoz, S., Ohtsuki, K. & Genda, H. (2017). "Ring formation around giant planets by a single encounter of Kuiper belt object". Icarus, 282, 195-213
    arXiv:1609.02396 Icarus, 282, 159-213
  48. Hyodo, R., Charnoz, S., Genda, H. & Ohtsuki, K. (2016). "Formation of Centaurs' Rings through Their Partial Tidal Disruption during Planetary Encounters". Astrophys. J. Letters, 828, L8
    arXiv:1608.03509 ApJL, 828, L8 ADS
  49. Rosenblatt, P., Charnoz, S., Dunseath, K.M., Terao-Dunseath, M., Trinh, A., Hyodo, R., Genda, H., & Toupi, S., (2016). "Accretion of Phobos and Deimos in an extended debris disc stirred by transient moons". Nature Geoscience, 9, 581
    Nature Geo. 9. 581 ADS
  50. Hyodo, R. & Ohtsuki, K., (2015). "Saturn's F ring and shepherd satellites a natural outcome of satellite system formation". Nature Geoscience, 8, 686-689
    Nature Geo. 8, 686-689 ADS
  51. Hyodo, R., Ohtsuki, K., Takeda, T., (2015). "Formation of multiple-satellite systems from low-mass circumplanetary particle disks". Astrophys. J., 799, 40
    arXiv:1411.4336 ApJ, 799, 40 ADS
  52. Hyodo, R. & Ohtsuki, K., (2014). "Collisional Disruption of Gravitational Aggregates in the Tidal Environment". Astrophys. J., 787, 56
    ApJ, 787, 56 ADS

Refereed Publications (Japanese)｜

  1. 兵頭龍樹 (2023) "惑星形成理論×惑星探査に関するある取り組み" 遊星人 32, 4-15.
    遊星人HP
  2. 荒川創太, 兵頭龍樹, 庄司大悟, 玄田英典 (2020) "太陽系外縁天体の衛星形成と潮汐進化" 遊星人 29, 104-114.
    遊星人HP
  3. 兵頭龍樹, 玄田英典 (2018) "火星衛星フォボスとデイモスの起源・進化の現状理解" 遊星人 27, 216-223.
    遊星人HP
  4. 兵頭龍樹, Sébastien Charnoz, 大槻圭史, 玄田英典 (2017) "多様な巨大惑星リングの形成過程について" 遊星人 26, 82-91.
    遊星人HP

Referees｜

  • NASA Proposal
  • Nature Geoscience
  • Nature Astronomy
  • Nature Communications
  • Science Advances
  • Astronomy & Astrophysics (A&A)
  • Astrophysical Journal (ApJ)
  • Astronomical Journal (AJ)
  • Planetary Science Journal (PSJ)
  • Monthly Notices of the Royal Astronomical Society (MNRAS)
  • Icarus
  • Earth, Moon, and Planets

iPhone Apps｜

[1] Kepler Motion (Expired), Ryuki Hyodo - 2014
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