Study of collisional disruption by using the ultra-high speed X-ray tomography and implication for the diversity of asteroid families

• Project/Area Number: 19H00719
• Research Category: Grant-in-Aid for Scientific Research (A)
• Allocation Type: Single-year Grants
• Section: 一般
• Review Section: Medium-sized Section 17:Earth and planetary science and related fields
• Research Institution: Kobe University
• Principal Investigator: Masahiko Arakawa 神戸大学, 理学研究科, 教授 (10222738)
• Co-Investigator(Kenkyū-buntansha): 保井 みなみ 神戸大学, 理学研究科, 講師 (30583843) ; 白井 慶 神戸大学, 理学研究科, 特命技術員 (90870519) ; 長谷川 直 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, 主任研究開発員 (10399553) ; 小川 和律 神戸大学, 理学研究科, 技術専門職員 (40509824)
• Project Period (FY): 2019-04-01 – 2022-03-31
• Project Status: Completed (Fiscal Year 2021)
• Budget Amount: ¥46,410,000 (Direct Cost: ¥35,700,000、Indirect Cost: ¥10,710,000); Fiscal Year 2021: ¥10,270,000 (Direct Cost: ¥7,900,000、Indirect Cost: ¥2,370,000); Fiscal Year 2020: ¥10,270,000 (Direct Cost: ¥7,900,000、Indirect Cost: ¥2,370,000); Fiscal Year 2019: ¥25,870,000 (Direct Cost: ¥19,900,000、Indirect Cost: ¥5,970,000)
• Keywords: 衝突破壊強度 / 小惑星 / 微惑星 / 熱進化天体 / フラッシュX線 / 再集積 / ラブルパイル天体 / デジタル画像相関法 / 小惑星族 / カタストロフィック破壊 / 衝突実験 / 熱進化 / 小惑星母天体 / 衝突破壊・再集積 / 層構造天体 / カタストロフック破壊 / 母天体 / 衝突破壊 / トモグラフィー

Outline of Research at the Start

微惑星内部の熱進化過程は、小惑星族の研究から再構築が可能である。本研究では、衝突破壊時に作られる破片の由来を調べるために、新しい実験解析手法を開発する。それは、4台のフラッシュX線を用いた超高速X線トモグラフィーである。この手法を熱進化した微惑星の模擬試料を使った高速度衝突実験に応用する。そして、衝突破片の3次元形状とその飛翔速度をX線トモグラフィーにより決定する。この衝突実験の結果を初期条件として衝突破片の重力再集積の数値計算を行って小惑星族を再現する。その結果、小惑星族を構成する個々の小惑星に集積した破片の由来を特定し、微惑星内部の熱進化過程を再構築する。

Outline of Final Research Achievements

The mass-velocity distribution of impact fragments at the time of collisional disruption was measured by analyzing the images taken by Flash X-rays and the images acquired by a high-speed camera by the digital image correlation method. Impact experiments were performed using targets that simulate the various stages of thermal evolution of planetesimals. From the comparison with the numerical simulation, it became clear that the impact strength QD* in the gravity-dominated regime can be estimated from the semi-theoretical formula by using the relationship between the median velocity v* and the energy density Q obtained in the laboratory experiment. It was found that QD* is sensitive to porosity and internal structure, but insensitive to tensile strength.

Academic Significance and Societal Importance of the Research Achievements

本研究の学術的意義は、熱進化する微惑星の衝突破壊強度を実験と数値シミュレーションにより明らかにし、小惑星の多様性を解明するための基礎を築いた点にある。
微惑星は熱進化と伴に重力支配域の衝突破壊強度が小さくなるので、初期成長時には、その成長が阻害される。一方、一端成長して二層構造になると衝突寿命が長くなり、熱進化を継続できることが分かった。これが分化した小惑星（M型やV型など）の破片と思われる小惑星の比率が、始原的小惑星（S型やC型）よりもかなり小さい理由なのかもしれない。

Research Products

• [Int'l Joint Research] ベルン大学(スイス)
• [Int'l Joint Research] ベルン大学(スイス)
• [Journal Article] Dispersion and shattering strength of rocky and frozen planetesimals studied by laboratory experiments and numerical simulations (2022)
  • Author(s): Arakawa Masahiko、Okazaki Masashi、Nakamura Masato、Jutzi Martin、Yasui Minami、Hasegawa Sunao
  • Journal Title: Icarus Volume: 373 Pages: 114777-114777
  • DOI: 10.1016/j.icarus.2021.114777
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] The Appearance of a “Fresh” Surface on 596 Scheila as a Consequence of the 2010 Impact Event (2022)
  • Author(s): Hasegawa Sunao、Marsset Michael、DeMeo Francesca E.、Bus Schelte J.、Ishiguro Masateru、Kuroda Daisuke、Binzel Richard P.、Hanus Josef、Nakamura Akiko M.、Yang Bin、Vernazza Pierre
  • Journal Title: The Astrophysical Journal Letters Volume: 924 Issue: 1 Pages: L9-L9
  • DOI: 10.3847/2041-8213/ac415a
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Impacts may provide heat for aqueous alteration and organic solid formation on asteroid parent bodies (2021)
  • Author(s): Yasui Minami、Tazawa Taku、Hashimoto Ryohei、Arakawa Masahiko、Ogawa Kazunori
  • Journal Title: Communications Earth & Environment Volume: 2 Issue: 1 Pages: 95-95
  • DOI: 10.1038/s43247-021-00159-x
  • NAID: 120007097083
  • Peer Reviewed / Open Access
• [Journal Article] Resurfacing processes on asteroid (162173) Ryugu caused by an artificial impact of Hayabusa2's Small Carry-on Impactor (2021)
  • Author(s): Honda Rie、Arakawa Masahiko、Shimaki Yuri、Shirai Kei、Yokota Yasuhiro、Kadono Toshihiko、Wada Koji、et al.
  • Journal Title: Icarus Volume: 366 Pages: 114530-114530
  • DOI: 10.1016/j.icarus.2021.114530
  • Peer Reviewed / Int'l Joint Research
• [Journal Article] Tensile strength and elastic properties of fine-grained ice aggregates: Implications for crater formation on small icy bodies (2021)
  • Author(s): Shimaki Yuri、Arakawa Masahiko
  • Journal Title: Icarus Volume: 369 Pages: 114646-114646
  • DOI: 10.1016/j.icarus.2021.114646
  • Peer Reviewed
• [Journal Article] Experimental study concerning the oblique impact of low- and high-density projectiles on sedimentary rocks (2021)
  • Author(s): Suzuki Ayako I.、Fujita Yoichi、Harada Shunya、Kiuchi Masato、Koumoto Yasunari、Matsumoto Eri、Omura Tomomi、Shigaki Sae、Taguchi Erine、Tsujido Sayaka、Kurosawa Kosuke、Hasegawa Sunao、Hirai Takayuki、Tabata Makoto、Tamura Hideki、Kadono Toshihiko、Nakamura Akiko M.、Arakawa Masahiko、Sugita Seiji、Ishibashi Ko
  • Journal Title: Planetary and Space Science Volume: 195 Pages: 105141-105141
  • DOI: 10.1016/j.pss.2020.105141
  • Peer Reviewed
• [Journal Article] Size of particles ejected from an artificial impact crater on asteroid 162173 Ryugu (2021)
  • Author(s): Wada K.、Ishibashi K.、Kimura H.、Arakawa M.、Sawada H.、Ogawa K.、Shirai K.、Honda R.、Iijima Y.、Kadono T.、Sakatani N.、Mimasu Y.、Toda T.、Shimaki Y.、Nakazawa S.、Hayakawa H.、Saiki T.、Takagi Y.、Imamura H.、Okamoto C.、Hayakawa M.、Hirata N.、Yano H.
  • Journal Title: Astronomy & Astrophysics Volume: 647 Pages: A43-A43
  • DOI: 10.1051/0004-6361/202039777
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Discovery of Two TNO-like Bodies in the Asteroid Belt (2021)
  • Author(s): Hasegawa Sunao、Marsset Michael、DeMeo Francesca E.、Bus Schelte J.、Geem Jooyeon、Ishiguro Masateru、Im Myungshin、Kuroda Daisuke、Vernazza Pierre
  • Journal Title: The Astrophysical Journal Letters Volume: 916 Issue: 1 Pages: L6-L6
  • DOI: 10.3847/2041-8213/ac0f05
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] An artificial impact on the asteroid 162173 Ryugu formed a crater in the gravity-dominated regime (2020)
  • Author(s): Arakawa, M., Saiki, T., Wada, K., Ogawa, K., Kadono, T., Shirai, K., Sawada, H., Ishibashi, K., Honda, R., Sakatani, N., Iijima, Y., Okamoto, C., Yano, H., Takagi, Y., Hayakawa, M., Michel, P., Jutzi, M., Shimaki, Y., Kimura, S., Mimasu, Y., Toda, T., Imamura, H., Nakazawa, S., Hayakawa, H., Sugita, S., et al.
  • Journal Title: Science Volume: 368 Issue: 6486 Pages: 67-71
  • DOI: 10.1126/science.aaz1701
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Journal Article] Impact Experiment on Asteroid (162173) Ryugu: Structure beneath the Impact Point Revealed by In Situ Observations of the Ejecta Curtain (2020)
  • Author(s): Kadono Toshihiko、Arakawa Masahiko、Honda Rie、Ishibashi Ko、Ogawa Kazunori、Sakatani Naoya、Sawada Hirotaka、Shimaki Yuri、Shirai Kei、Sugita Seiji、Wada Koji
  • Journal Title: The Astrophysical Journal Volume: 899 Issue: 1 Pages: L22-L22
  • DOI: 10.3847/2041-8213/aba949
  • Peer Reviewed
• [Journal Article] Measurements of seismic waves induced by high-velocity impacts: Implications for seismic shaking surrounding impact craters on asteroids (2020)
  • Author(s): Matsue Kazuma、Yasui Minami、Arakawa Masahiko、Hasegawa Sunao
  • Journal Title: Icarus Volume: 338 Pages: 113520-113520
  • DOI: 10.1016/j.icarus.2019.113520
  • NAID: 120006818762
  • Peer Reviewed
• [Journal Article] Effects of oblique impacts on the impact strength of porous gypsum and glass spheres: Implications for the collisional disruption of planetesimals in thermal evolution (2020)
  • Author(s): Yasui Minami、Arakawa Masahiko、Yoshida Yusaku、Matsue Kazuma、Takano Shota
  • Journal Title: Icarus Volume: 335 Pages: 113414-113414
  • DOI: 10.1016/j.icarus.2019.113414
  • NAID: 120006818761
  • Peer Reviewed
• [Journal Article] Q-type asteroids: Possibility of non-fresh weathered surfaces (2019)
  • Author(s): Hasegawa, S., Hiroi, T., Ohtsuka, K., Ishiguro, M., Kuroda, D., Ito, T., Sasaki, S.
  • Journal Title: Publications of the Astronomical Society of Japan Volume: 71 Issue: 5 Pages: 103-103
  • DOI: 10.1093/pasj/psz088
  • Peer Reviewed / Open Access / Int'l Joint Research
• [Presentation] Post Shock Heat Induced by High Velocity Impact on Porous Icy Bodies (2022)
  • Author(s): Sasai, H., Yasui, M., Arakawa, M., Shirai, K.
  • Organizer: 53rd Lunar and Planetary Science Conference
  • Int'l Joint Research
• [Presentation] Impact Strength of Porous- and Ductile-Rocky Planetesimals in Gravity Dominated Regime (2022)
  • Author(s): Arakawa, M., Nagano, T., Ishida, S., Yasui, M., Shirai, K., Hasegawa, S.
  • Organizer: 53rd Lunar and Planetary Science Conference
  • Int'l Joint Research
• [Presentation] High-Velocity Impact Experiments of Simulated Porous Asteroids and Measurements of Post Impact Temperature around Impact Crater (2022)
  • Author(s): Yasui, M., Tazawa, T., Hashimoto, R., Arakawa, M., Ogawa, K.
  • Organizer: 53rd Lunar and Planetary Science Conference
  • Int'l Joint Research
• [Presentation] Constraining Asteroid Ryugu’s Surface Properties from Numerical Simulations of the SCI Impact (2022)
  • Author(s): Jutzi, M., Raducan, S. D., Zhang, Y., Michel, P., Arakawa, M.
  • Organizer: 53rd Lunar and Planetary Science Conference
  • Int'l Joint Research
• [Presentation] 氷微惑星上の高速衝突により発生する衝突残留熱の定量的評価 (2021)
  • Author(s): 笹井遥，荒川政彦，保井みなみ，白井慶
  • Organizer: 日本惑星科学会2021年秋季講演会
• [Presentation] フラッシュ X 線による衝突破片の速度―質量分布の計測: 粘土を用いた延性標的の衝突破壊実験 (2021)
  • Author(s): 長野巧，荒川政彦，保井みなみ，石田紗那，長谷川直
  • Organizer: 日本惑星科学会2021年秋季講演会
• [Presentation] 層構造含水微惑星の模擬物質への衝突実験：デジタル画像相関法による標的内部の粒子速度分布の計測 (2021)
  • Author(s): 石田紗那，荒川政彦，保井みなみ，白井慶，長谷川直，長野巧，堀川和洋
  • Organizer: 日本惑星科学会2021年秋季講演会
• [Presentation] 熱進化した氷微惑星の斜め衝突に関する実験的研究 (2021)
  • Author(s): 中村誠人，保井みなみ，荒川政彦
  • Organizer: 日本惑星科学会2021年秋季講演会
• [Presentation] 彗星核を模擬した多孔質氷に対する高速度衝突実験：衝突残留熱へのエネルギー分配率 (2021)
  • Author(s): 笹井遥，保井みなみ，荒川政彦，白井慶
  • Organizer: JpGU2021
• [Presentation] 小惑星衝突時の運動量輸送に関する実験的研究 (2021)
  • Author(s): 堀川和洋，荒川政彦，保井みなみ，白井慶，長谷川直
  • Organizer: JpGU2021
• [Presentation] 層構造試料を用いた衝突破壊実験：デジタル画像相関法による衝突破片速度分布の計測法の開発 (2021)
  • Author(s): 石田紗那，荒川政彦，保井みなみ，白井慶，堀川和洋
  • Organizer: JpGU2021
• [Presentation] 低空隙多孔質氷標的を用いた高速度衝突実験：運動量輸送およびクレーター形成過程に関する実験的研究 (2021)
  • Author(s): 江口裕樹，荒川政彦，保井みなみ，笹井遥
  • Organizer: JpGU2021
• [Presentation] Artificial impact crater on Ryugu formed in the gravity dominated regime (2021)
  • Author(s): M. Arakawa, K. Wada, K. Ogawa, T. Kadono, K. Shirai, K. Ishibashi, R. Honda, N. Sakatani, Y. Shimaki
  • Organizer: 7th IAA Planetary Defense Conference
  • Int'l Joint Research
• [Presentation] Impact cratering experiments on granular targets simulating surface layer on asteroid 162173 Ryugu: Crater scaling law and impact induced seismic shaking (2021)
  • Author(s): Yasui, M., Arakawa, M., Okawa, H., Hasegawa, S.
  • Organizer: 52nd Lunar and Planetary Science Conference
  • Int'l Joint Research
• [Presentation] Three-dimensional tracking of various sized glass beads ejected from impact crater (2021)
  • Author(s): Okawa, H., Arakawa, M., Yasui, M., Hasegawa, S., Yokota, Y., Yamamoto, Y
  • Organizer: 52nd Lunar and Planetary Science Conference
  • Int'l Joint Research
• [Presentation] Crater size scaling law and impact-induced seismic shaking on rubble-pile asteroids (2021)
  • Author(s): Yamamoto, Y., Arakawa, M., Yasui, M., Hasegawa, S., Yokota, Y., Okawa, H., Sugimura, R.
  • Organizer: 52nd Lunar and Planetary Science Conference
  • Int'l Joint Research
• [Presentation] High velocity impact experiments on porous ice aggregates simulating cometary nuclei surface: Measurements of post shock temperature around impact crater (2021)
  • Author(s): Sasai, H., Yasui, M., Arakawa, M., Shirai, K.
  • Organizer: 52nd Lunar and Planetary Science Conference
  • Int'l Joint Research
• [Presentation] Experimental study on impact craters formed on mountain-like surface topography of asteroids (2021)
  • Author(s): Yokota, Y., Arakawa, M., Yasui, M., Yamamoto, Y., Okawa, H., Hasegawa, S.
  • Organizer: 52nd Lunar and Planetary Science Conference
  • Int'l Joint Research
• [Presentation] A hybrid SPH-SSDEM framework for end-to-end impact cratering modeling (2021)
  • Author(s): Zhang, Y., Jutzi, M., Michel, P., Raducan, S. D., Arakawa, M.
  • Organizer: 52nd Lunar and Planetary Science Conference
  • Int'l Joint Research
• [Presentation] Resurfacing processes on asteroid (162173) Ryugu caused by an artificial impact of Hayabusa2’s Small Carry-on Impactor (2020)
  • Author(s): Arakawa, M., Honda, R., Yokota, Y., Shimaki, Y., Shirai, K., Kadono, T., Wada, K., Ogawa, K., Ishibashi, K., Sakatani, N., Yasui, M., Morota, T., Kameda, S., Tatsumi, E., Yamada, M., Kouyama, T., Cho, Y., Matsuoka, M., Suzuki, H., Honda, C., Hayakawa, M., Yoshioka, K., Sawada, H., Sugita, S., Hirata, N., Hirata, N.
  • Organizer: 52nd Meeting of the AAS Division for Planetary Sciences
  • Int'l Joint Research
• [Presentation] Artificial impact crater formed by Small Carry-on Impactor on the asteroid 162173 Ryugu in the gravity-dominated regime (2020)
  • Author(s): Arakawa M. et al. 他33名
  • Organizer: JpGU-AGU Joint Meeting 2020
  • Int'l Joint Research / Invited
• [Presentation] フラッシュX線による衝突破片の速度ー質量分布の計測：粘土を用いた延性標的の衝突破壊実験 (2020)
  • Author(s): 長野巧，荒川政彦，保井みなみ，堀川和洋
  • Organizer: 日本惑星科学会2020年度秋季講演会（会津）
• [Presentation] 低強度標的を用いた衝突破壊実験:引張強度と衝突破壊強度の関係 (2020)
  • Author(s): 堀川和洋，荒川政彦，保井みなみ，杉村瞭
  • Organizer: JpGU-AGU Joint Meeting 2020
• [Presentation] 弱い強度を持つ表面への衝突クレーター形成実験とクレータースケール則の構築 (2020)
  • Author(s): 杉村瞭，荒川政彦，保井みなみ，千秋博紀，長谷川直
  • Organizer: JpGU-AGU Joint Meeting 2020
• [Presentation] 氷微惑星の衝突破壊強度に対する斜め衝突の効果 (2020)
  • Author(s): 中村誠人，保井みなみ，荒川政彦
  • Organizer: JpGU-AGU Joint Meeting 2020
• [Presentation] 多孔質氷上のクレーター形成に伴う衝突残留温度の計測 (2020)
  • Author(s): 笹井遥，保井みなみ，荒川政彦，中村誠人
  • Organizer: JpGU-AGU Joint Meeting 2020
• [Presentation] 多孔質氷天体を模擬したクレーター形成実験：衝突残留熱の計測 (2020)
  • Author(s): 笹井遥，荒川政彦，保井みなみ，白井慶
  • Organizer: 日本惑星科学会2020年度秋季講演会（会津）
• [Presentation] 衝突残留熱と小惑星母天体の熱変成過程に関する実験的研究 (2020)
  • Author(s): 保井みなみ，田澤拓，橋本涼平，荒川政彦，小川和律
  • Organizer: 日本惑星科学会2020年度秋季講演会（会津）
• [Presentation] Experimental study on collision destruction simulating the primitive meteorite parent body (2019)
  • Author(s): 堀川 和洋, 荒川 政彦, 保井 みなみ, 杉村 瞭
  • Organizer: 日本地球惑星科学連合2019年大会
• [Presentation] Experimental study on impact crater formed on bulge (2019)
  • Author(s): Yusaku Yokota, Yuya Yamamoto, Minami Yasui, Masahiko Arakawa, Haruka Sasai
  • Organizer: Japan Geoscience Union Meeting 2019
  • Int'l Joint Research
• [Presentation] Impact cratering experiments on glass beads with bead size freuency distribution: Implications for cratering process on asteroid Ryugu (2019)
  • Author(s): Minami Yasui, Masahiko Arakawa, Sunao Hasegawa, Yuya Yamamoto, Ryo Sugimura
  • Organizer: Japan Geoscience Union Meeting 2019
  • Int'l Joint Research
• [Presentation] Impact experiment on asteroid Ryugu by Small-Carry on impactor of Hayabusa-2 and observation of the impact ejecta by a Deployable CAMera-3 (2019)
  • Author(s): Masahiko Arakaw et al.
  • Organizer: Japan Geoscience Union Meeting 2019
  • Int'l Joint Research / Invited
• [Presentation] Impact experiments on low strength coarse-grained regolith simulating surface materials on asteroid Ryugu (2019)
  • Author(s): Yuya Yamamoto, Masahiko Arakawa, Minami Yasui, Sunao Hasegawa, Ryo Sugimura
  • Organizer: Japan Geoscience Union Meeting 2019
  • Int'l Joint Research
• [Presentation] Observation of catastrophic destruction of two different targets using X Ray photography (2019)
  • Author(s): 長野 巧, 荒川 政彦, 保井 みなみ, 中村 誠人, 長友 文哉
  • Organizer: 日本地球惑星科学連合2019年大会
• [Presentation] 小惑星表面を模擬した砂・石膏標的を用いた高速度クレーター形成実験 (2019)
  • Author(s): 杉村 瞭, 荒川 政彦, 保井 みなみ, 石黒 琢也
  • Organizer: 日本地球惑星科学連合2019年大会
• [Presentation] First result of Hayabusa2 impact experiment on Ryugu (2019)
  • Author(s): Masahiko Arakawa, The Hayabusa2 SCI/DCAM3 and ONC team
  • Organizer: EPSC-DPS Joint Meeting 2019
  • Int'l Joint Research
• [Presentation] Impact experiments on granular targets with size frequency distribution similar to asteroid 162173 Ryugu (2019)
  • Author(s): Minami Yasui, Yuya Yamamoto, Masahiko Arakawa, Sunao Hasegawa, Ryo Sugimura, Yusaku Yokota
  • Organizer: EPSC-DPS Joint Meeting 2019
  • Int'l Joint Research
• [Presentation] In-situ observation of catastrophic disruption of asteroid analogues using flash X-ray photography (2019)
  • Author(s): Masahiko Arakawa, Minami Yasui, Masashi Okazaki, Masato Nakamura, Sunao Hasegawa
  • Organizer: EPSC-DPS Joint Meeting 2019
  • Int'l Joint Research
• [Presentation] フラッシュX線を用いた衝突破壊現象の観測：多孔質標的の破片速度分布に対する空隙の効果 (2019)
  • Author(s): 中村 誠人, 荒川 政彦, 保井 みなみ, 長谷川 直
  • Organizer: 日本惑星科学会2019年秋季大会
• [Presentation] Artificial impact crater formed by Hayabusa2 small carry-on impactor on the surface of asteroid Ryugu (2019)
  • Author(s): Masahiko Arakaw et al.
  • Organizer: American Geophysical Union(AGU) Fall Meeting 2019
  • Int'l Joint Research / Invited
• [Presentation] はやぶさ2 SCIによる小惑星リュウグウ上での衝突実験 (2019)
  • Author(s): 荒川政彦 他
  • Organizer: 日本惑星科学会2019年秋季大会
  • Invited