超高速レーザー銃実験による惑星間衝突の実験的研究

2010 Fiscal Year Annual Research Report

• Project/Area Number: 21244069
• Research Institution: Chiba Institute of Technology
• Principal Investigator: 松井 孝典 千葉工業大学, 惑星探査研究センター, 所長 (80114643)
• Co-Investigator(Kenkyū-buntansha): 杉田 精司 東京大学, 大学院・新領域創成科学研究科, 教授 (80313203) ; 門野 敏彦 大阪大学, レーザーエネルギー学研究センター, 准教授 (60359198) ; 中村 昭子 神戸大学, 大学院・理学研究科, 准教授 (40260012) ; 荒川 政彦 神戸大学, 大学院・理学研究科, 教授 (10222738)
• Keywords: レーザー銃 / 惑星進化 / 天体衝突 / 衝突蒸気雲 / 衝撃波 / 高速分光法 / 原子分光法 / 状態方程式

Research Abstract

本年度は、東京大学柏キャンパスおよび大阪大学レーザーエネルギー学研究センターの大型レーザーを用いて、3つの大きな課題に取り組んだ。具体的には、(1)超高速(>10km/s)衝撃条件下でのケイ酸塩鉱物の比熱計測および断熱緩和過程中における電離状態・解離状態の分光計測、(2)超高速(>10km/s)衝突による硫酸塩岩の脱ガスの分子組成の直接計測、(3)アンモニア・水混合氷の衝突脱ガス分子組成の直接計測、の3つである。第1のケイ酸塩の比熱計測からは、宇宙速度における衝突では、石英も輝石もその比熱が常温常圧状態に比べて数倍にまで上昇することが明らかになった。これは、天体衝突に際してのエントロピー増加が従来予想よりも遙かに大きいこと及び断熱膨張による衝突蒸気雲の加速が従来予想より遙かに長い時間にわたって起きることの2つを示している。これは、月を形成したとされる巨大衝突に際して周地球円盤の形成条件を大きく変更することになる可能性が高く、惑星科学的に非常に大きな意義がある。第2の硫酸塩岩の脱ガス分子組成計測からは、SO_3の大量生成が初めて明確に示された。これは、K/Pg衝突事件において地球規模の硫酸雨が降って大量絶滅が起きた可能性を強く示唆している。第3のアンモニア・水氷の衝突脱ガス計測からは、タイタンのN_2大気が、内部からの火山活動による連続脱ガスにも外部からのN_2直接持ち込みにも頼らず、地殻に豊富に含まれるアンモニアの衝突分解過程によって形成できることを示す結果を得た。これは、惑星大気の起源について、従来のどの仮説とも異なり、今後の惑星大気起源論において重要な役割を果たすことが期待される.

Research Products

• [Journal Article] A ground-based observation of the LCROSS impact events using the Subaru Telescope (2011)
  • Author(s): Hong, P. K., S. Sugita, N. Okamura, Y. Sekine, H. Terada, N. Takatoh, Y. Hayano, T. Fuse, T.-S. Pyo, H. Kawakita, D. H. Wooden, E. F. Young, P. G. Lucey, K. Kurosawa, H. Genda, J. Haruyama, R. Furusho, T. Kadono, R. Nakamura, S. Kamata, T. Hamura, T. Sekiguchi, M. Soma, H. Noda, J. Watanabe
  • Journal Title: Icarus Volume: 214 Pages: 21-29
  • Peer Reviewed
• [Journal Article] Replacement and late formation of atmospheric N_2 on undifferentiated Titan by impacts (2011)
  • Author(s): Sekine, Y., H.Genda, S.Sugita, T.Kadono, T.Matsui
  • Journal Title: Nature Geoscience Volume: 4 Pages: 359-362
  • DOI: 10.1038/ngeo1147
  • Peer Reviewed
• [Journal Article] LCROSS (Lunar Crater Observation and Sensing Satellite) Observation Campain : Strategies, Implementation, and Lessons Learned (2011)
  • Author(s): Heldman, J.L., A.Colaporete, D.H.Wooden, et al.
  • Journal Title: Space Science Review Volume: (印刷中)
  • Peer Reviewed
• [Journal Article] Experimental study on the rheological properties of polycrystalline solid nitrogen and methane : Implications for tectonic processes on Triton (2010)
  • Author(s): Yamashita, Y., M. Kato, and M. Arakawa
  • Journal Title: Icarus Volume: 207 Pages: 972-977
  • Peer Reviewed
• [Journal Article] 高速レーザー銃がもたらす惑星間衝突物理学の進展 (2010)
  • Author(s): 杉田精司, 黒澤耕介, 門野敏彦
  • Journal Title: プラズマ・核融合学会誌 Volume: 86 Pages: 589-593
• [Journal Article] In-situ spectroscopic observations of silicate vaporization due to >10km/s impacts using laser driven projectiles (2010)
  • Author(s): Kurosawa K., S.Sugita, T.Kadono, K.Shigemori, Y.Hironaka, K.Otani, T.Sano, A.Shiroshita, N.Ozaki, K.Miyanishi, T.Sakaiya, Y.Sekine, S.Tachibana, K.Nakamura, S.Fukuzaki, S.Ohno, R.Kodama, T.Matsui
  • Journal Title: Geophysical Research Letters Volume: 37 Pages: doi:10.1029/2010GL045330
  • Peer Reviewed
• [Journal Article] Impact-induced N_2 production from ammonium sulfate (NH_4)_2SO_4 : Implications for the origin and evolution of N_2 in Titan's atmosphere (2010)
  • Author(s): Fukuzaki, S., Y.Sekine, H.Genda, S.Sugita, T.Kadono, T.Matsui
  • Journal Title: Icarus Volume: 209 Pages: 715-722
  • Peer Reviewed
• [Journal Article] A hydrocode calculation coupled with reaction kinetics of carbon compounds within animpact vapor plume and its implications for cometary impacts on Galilean satellites (2010)
  • Author(s): Ishimaru, R., H.Senshu, S.Sugita, T.Matsui
  • Journal Title: Icarus Volume: 210 Pages: 411-423
  • Peer Reviewed
• [Journal Article] A pressure measurement method for high-temperature rock vapor plumes using atomic line broadening (2010)
  • Author(s): Kurosawa, K., S.Sugita
  • Journal Title: Journal of Geophysical Research Volume: 115 Pages: doi:10.1029/2010JE003575
  • Peer Reviewed
• [Journal Article] 宇宙速度衝突による珪酸塩蒸発過程のその場時間分解発光分光観測 (2010)
  • Author(s): 黒澤耕介, 門野敏彦, 杉田精司, 重森啓介, 弘中陽一郎, 尾崎典雅, 城下明之, 長勇一郎, 境家達弘, 橘省吾, 大野宗祐, 藤岡慎介, Tommaso Vinci, 兒玉了祐, 松井孝典
  • Journal Title: 日本惑星科学誌 遊星人 Volume: 19 Pages: 332-339
  • Peer Reviewed
• [Journal Article] High-Speed Time-Series Spectroscopic and Imaging Observations on Aerodynamic Ablation Processes within Vapor Plumes due to Oblique Impacts (2010)
  • Author(s): Hamura, T., K.Kurosawa, S.Hasegawa, T.Matsui, S.Sugita
  • Journal Title: Proceedings of 43th Lunar and Planetary Symposium Volume: 42(印刷中)
• [Journal Article] LCROSS衝突の放出物のすばる望遠鏡による地上観測 (2010)
  • Author(s): 洪鵬, 岡村奈津子, 杉田精司, 関根康人, 寺田宏, 高遠徳尚, 早野裕, 布施哲治, 河北秀世, 黒澤耕介, 春山純一, 古荘玲子, 門野敏彦, 中村良介, 羽村太雅, 関口朋彦, 渡部潤一
  • Journal Title: 日本惑星科学会誌 遊星人 Volume: 19 Pages: 96-104
  • Peer Reviewed
• [Journal Article] Experimental study on static and impact strength of sintered agglomerates (2010)
  • Author(s): Machii, N., Nakamura, A.M
  • Journal Title: Icarus Volume: 211 Pages: 885-893
  • Peer Reviewed
• [Journal Article] The Hayabusa spacefract asteroid multi-band imaging camera : AMICA (2010)
  • Author(s): Ishiguro, M., ほか(15著者の7番めにNakamura, A.M.)
  • Journal Title: Icarus Volume: 207 Pages: 714-731
  • Peer Reviewed
• [Journal Article] The shape distribution of boulders on asteroid 25143 Itokawa : Comparison with fragments from impact experiments (2010)
  • Author(s): Michikami, T., A.M.Nakamura, N.Hirata
  • Journal Title: Icarus Volume: 207 Pages: 277-284
  • Peer Reviewed
• [Journal Article] In Situ Observation of Penetration Process in Silica Aerogel : Deceleration Mechanism of Hard Spherical Projectiles. (2010)
  • Author(s): Niimi, R., T.Kadono, M.Arakawa, M.Yasui, K.Dohi, A.M.Nakamura, Y.Iida, A.Tsuchiyama
  • Journal Title: Icarus Volume: 211 Pages: 986-992
  • Peer Reviewed
• [Journal Article] Rate-dependent strength of porous ice-silica mixtures and its implications for the shape of small to middle-sized icy satellites (2010)
  • Author(s): Yasui, M., M.Arakawa
  • Journal Title: Icarus Volume: 210 Pages: 956-967
  • Peer Reviewed
• [Presentation] Experimental study of SO_3/SO_2 ratio in impact vapor clouds using a high-speed laser gun (2011)
  • Author(s): S.Ohno, T.Kadono, K.Kurosawa, T.Hamura, T.Sakaiya, S.Sugita, K.Shigemori, Y.Hironaka, T.Watari, T.Matsui
  • Organizer: Lunar and Planetary Science Conference, XXXXII
  • Place of Presentation: The Woodlands, Texas, (U.S.A.)
  • Year and Date: 2011-03-08
• [Presentation] Experimental results investigating impact velocity effects of crater growth and the transiet depth-diameter ratio (2011)
  • Author(s): Barnouin, O.S., J.T.Heinick, S.Sugita, M.T.Cintala, D.A.Crawford, T.Matsui
  • Organizer: Lunar and Planetary Science Conference, XXXXII
  • Place of Presentation: The Woodlands, Texas, (U.S.A.)
  • Year and Date: 2011-03-08
• [Presentation] Prediction of the elecmental composition of olivine by laser-induced breakdown spectroscopy (LIBS) (2011)
  • Author(s): K.Ishibashi, S.Ohnno, T.Arai, K.Wada, S.Kameda, H.Senshu, N.Namiki, T.Matsui, Y.Cho, S.Sugita
  • Organizer: Lunar and Planetary Science Conference, XXXXII
  • Place of Presentation: The Woodlands, Texas, (U.S.A.)
  • Year and Date: 2011-03-08
• [Presentation] Pressure measurements of self-luminous rock vapors using atomic line broadening (2011)
  • Author(s): K.Kurosawa, S.Sugita
  • Organizer: Lunar and Planetary Science Conference, XXXXII
  • Place of Presentation: The Woodlands, Texas, (U.S.A.)
  • Year and Date: 2011-03-08
• [Presentation] A new modified Gaussian model (MGM) using a Bayesian estimation approach : toward automated analysis of planetary spectra (2011)
  • Author(s): Sugita, S., N.Nagata, N.Tsuboi, T.Hiroi, M.Okada
  • Organizer: Lunar and Planetary Science Conference, XXXXII
  • Place of Presentation: The Woodlands, Texas, (U.S.A.)
  • Year and Date: 2011-03-08
• [Presentation] Radiogenic heat source concentration in the lunar farside crust estimated from visocoelastic deformation of impact basins (2011)
  • Author(s): S.Kamata, S.Sugita, Y.Abe, Y.Ishi-hara, Y.Harada, N.Namiki, T.Iwata, H.Hanada, H.Araki
  • Organizer: Lunar and Planetary Science Conference, XXXXII
  • Place of Presentation: The Woodlands, Texas, (U.S.A.)
  • Year and Date: 2011-03-08
• [Presentation] Impact compaction experiments on high-porosity sintered targets (2011)
  • Author(s): Okamoto, T., Nakamura, A.M., Hasegawa, S., Tsuchiyama.A., Ikezaki, K.
  • Organizer: East Asia Young Astronomers Meeting 2011
  • Place of Presentation: 済州島(韓国)
  • Year and Date: 2011-02-17
• [Presentation] Ejecta size distribution from hypervelocity impact cratering of planetary materials : Implication for dust production process of impact origin (2010)
  • Author(s): Takasawa, S., Nakamura, A.M., Kadono, T., Arakawa, M., Dohi, K., Ohno, S., Seto, Y., Maeda, M., Shigemori, K., Hironaka, Y., Sakaiya, T., Sano, T., Watari, T., Sangen, K., Takeuchi, T.
  • Organizer: European Planetary Science Congress 2010
  • Place of Presentation: Rome (Italy)
  • Year and Date: 2010-09-24
• [Presentation] Flyer acceleration using high-power laser and impact experiments at velocities 10-60km/s (2010)
  • Author(s): Kadono, T., ほか9著者
  • Organizer: European Planetary Science Conference 2010
  • Place of Presentation: Roma (Italia)
  • Year and Date: 2010-09-23
• [Presentation] Measurements of post shock temperature deposited in ice impact crater (2010)
  • Author(s): Arakawa, M., M.Yasui
  • Organizer: 12th International conference on the Physics and Chemistry of Ice
  • Place of Presentation: Sapporo (Japan)
  • Year and Date: 2010-09-09
• [Presentation] Flyer Acceleration Using a High-Power Laser to Velocities Higher Than 10km/s (2010)
  • Author(s): Kadono, T., ほか12著者
  • Organizer: Western Pacific Geophysical Meeting 2010
  • Place of Presentation: Taipei (Taiwan)
  • Year and Date: 2010-06-22
• [Presentation] Experimental study on impact craters formed on layered crusts (2010)
  • Author(s): Arakawa, M., K.Dohi, C.Okamoto, S.Hasegawa
  • Organizer: 2010 Western Pacific Geophysics Meeting
  • Place of Presentation: Taipei (Taiwan)
  • Year and Date: 2010-06-22
• [Presentation] Experimental study on the impact disruption of rubble pile bodies (2010)
  • Author(s): Fujita, Y., M.Arakawa
  • Organizer: 2010 Western Pacific Geophysics Meeting, Taipei
  • Place of Presentation: Taipei (Taiwan)
  • Year and Date: 2010-06-22