Geological processes under an extremely small gravity : Effects of seismic-shaking

2010 Fiscal Year Final Research Report

• Project/Area Number: 20684019
• Research Category: Grant-in-Aid for Young Scientists (A)
• Allocation Type: Single-year Grants
• Research Field: Solid earth and planetary physics
• Research Institution: The University of Tokyo
• Principal Investigator: MIYAMOTO Hideaki The University of Tokyo, 総合研究博物館, 准教授 (00312992)
• Project Period (FY): 2008 – 2010
• Keywords: 小惑星 / レゴリス / 惑星探査 / 粉体 / 数値シミュレーション

Research Abstract

Detailed geological study of close-up images obtained by Hayabusa spacecraft reveal that some of the gravels hold bright spot, which indicate the age of surface blocks is 1-10Ma. This supports our view that the surface gravel is migrating occasionally on the surface of the asteroid Itokawa. We developed a numerical simulation code of three-dimensional rock particles with irregular shapes and find that the gravels in the close-up images obtained by Hayabusa spacecraft are geometrically saturated and thus their size-frequency distributions should be carefully used to discuss the internal structure of Itokawa. Also, we newly develop a theoretical model of migrations of gravels including electro-statically levitated fine particles. Our theoretical model indicates that the smoothness of Saturnian satellite, Atlas, can be explained by dust levitations, which might be the dominant resurfacing process on the surface of this satellite. This indicates that dust levitation can be another important global-scale resurfacing under an extremely small gravity.

Research Products

• [Journal Article] Surface morphological features of boulders on Asteroid 25143 Itokawa (2010)
  • Author(s): Noguchi T, Tsuchiyama A, Hirata N, Demura H, Nakamura R, Miyamoto H, Yano H, Nakamura T, Saito J, Sasaki S, HashimotoT, Kubota T, Ishiguro M,, Zolensky ME
  • Journal Title: Icarus 206 Pages: 319-326
• [Journal Article] イトカワの岩塊表面に分布する高輝度スポット:年代決定に利用できるか (2010)
  • Author(s): 竹内洋人, 宮本英昭, 丸山智志
  • Journal Title: 日本惑星科学会学会誌 19 Pages: 23-27
• [Journal Article] マイケル・E・ゾレンスキー,小惑星イトカワ表面に存在する岩塊の表面組織の解読～小惑星のフィールド岩石学の試み～ (2010)
  • Author(s): 野口高明, 平田成, 土'山明, 出村裕英, 中村良介, 宮本英昭, 矢野創, 中村智樹, 齋藤潤, 佐々木晶, 橋本樹明, 久保田孝, 石黒正晃
  • Journal Title: 日本惑星科学会学会誌 19 Pages: 12-22
• [Journal Article] The sedimentology and dynamics of crater-affiliated wind streaks in western Arabia Terra, Mars and Patagonia (2010)
  • Author(s): Rodriguez, JAP, Tanaka, K.L., Berman, D.C., Zimbelman, J.R, Kargel, J.S., Sasaki, S., Yan, J.G., Miyamoto, H.
  • Journal Title: Argentina, Geomorphology 121 Pages: 30-54
• [Journal Article] A survey of possible impact structures on 25143 Itokawa (2009)
  • Author(s): Hirata N, Barnouin-jha, O.S., Honda, C., Nakamura R., Miyamoto, H. Sasaki, S., Demura, H., nakamura, A.M., Michikami, T., Gaskell, R.W., Saito, J.
  • Journal Title: Icarus 200 Pages: 486-502
• [Journal Article] Long-lived volcanism on the lunar farside revealed by SELENE terrain camera (2009)
  • Author(s): Haruyama, J., Ohtake, M., Matsunaga, T., Morota, T., Honda, C., Yokota, Y., Abe, M., Ogawa, Y., Miyamoto, Iwasaki, A., et al.
  • Journal Title: Science 323 Pages: 905-908
• [Journal Article] Lack of exposed ice inside lunar south pole Shackleton Crater (2008)
  • Author(s): Haruyama, J., Ohtake, M., Matsunaga, T., Morota, T., Honda, C., Yokota, Y., Pieters, C.M., Hara, S., Hiroki, K., Saiki, K., Miyamoto, H., Iwasaki, A., et al.
  • Journal Title: Science 322 Pages: 938-939
• [Journal Article] An Inventory of Potentially Habitable Environments on Mars : Geological and Biological Perspectives
  • Author(s): Dohm, J.M. Miyamoto, H., et al
  • Journal Title: Special Edition of Geological Society of America 印刷中
• [Presentation] Unusual smoothness of the surface of a saturnianicy satellite (2011)
  • Author(s): Hirata, N., Miyamoto, H.
  • Organizer: Atlas, Lunar and Planetary Science Conference
  • Place of Presentation: 米国・テキサス州
  • Year and Date: 2011-03-15
• [Presentation] Origins of Bright Spots on the Surface of Boulders Covering Asteroid Itokawa (2010)
  • Author(s): Takeuchi, H., Miyamoto, H., Maruyama, S,
  • Organizer: Lunar and Planetary Science Conference
  • Place of Presentation: 米国
  • Year and Date: 20100300
• [Presentation] Evidence for Global-Scale Inverse Grading of Regolith Materials on Asteroid Itokawa (2010)
  • Author(s): Maruyama, S., Miyamoto, H., Takeuchi, H.,Oku, M.,
  • Organizer: Lunar and Planetary Science Conference
  • Place of Presentation: 米国
  • Year and Date: 20100300
• [Presentation] Surface morphological features of boulders on Asteroid 25143 Itokawa (2010)
  • Author(s): Noguchi, T., Tsuchiyama, A., Hirata, N., Demura, H., Nakamura, R., Mimoto, H., Yano, H., Nakamura, T., Saito, J., Sasaki, S.
  • Organizer: Lunar and Planetary Science Conference
  • Place of Presentation: 米国
  • Year and Date: 20100300
• [Presentation] 光化学反応によるイオの硫黄濃集機構 (2010)
  • Author(s): 平田直之、宮本英昭
  • Organizer: 日本惑星科学会2010年秋季講演会
  • Place of Presentation: 名古屋市
  • Year and Date: 2010-10-06
• [Presentation] 土星系の小型衛星アトラスの地形と進化 (2010)
  • Author(s): 平田直之、宮本英昭
  • Organizer: 月惑星科学シンポジウム
  • Place of Presentation: 相模原市
  • Year and Date: 2010-08-05
• [Presentation] 固体天体用地中レーダー(GPR)システムの検討と開発 (2010)
  • Author(s): 渡邊宏弥、宮本英昭、西堀俊幸
  • Organizer: 月惑星科学シンポジウム
  • Place of Presentation: 相模原市
  • Year and Date: 2010-08-05
• [Presentation] イトカワにみられる岩塊の統計的解析:表層物質の逆分級 (2010)
  • Author(s): 丸山智志 宮本英昭 竹内洋人
  • Organizer: 日本地球惑星科学連合2010年大会
  • Place of Presentation: 幕張
  • Year and Date: 2010-05-26
• [Presentation] イトカワの岩塊表面に見られる高輝度スポット:形成過程と岩塊の年代 (2009)
  • Author(s): 竹内洋人, 宮本英昭, 奥元良, 丸山智志
  • Organizer: 日本惑星科学会秋期講演会
  • Place of Presentation: 東京
  • Year and Date: 20090900
• [Presentation] イトカワにみられる岩塊の統計的解析:表層物質の逆分級 (2009)
  • Author(s): 丸山智志, 宮本英昭, 竹内洋人
  • Organizer: 日本地球惑星科学連合連合大会
  • Place of Presentation: 千葉県
  • Year and Date: 2009-05-26
• [Presentation] 小惑星イトカワの岩塊表面に見られる高輝度スポットの分布と形態的特徴 (2009)
  • Author(s): 丸山智志, 宮本英昭, 竹内洋人
  • Organizer: 日本地球惑星科学連合連合大会
  • Place of Presentation: 千葉県
  • Year and Date: 2009-05-26
• [Presentation] Distributions and Morphological Characteristics of Bright Spots on Boulders Covering the Surface of Asteroid Itokawa (2009)
  • Author(s): Takeuchi, H., H. Miyamoto, M. Oku
  • Organizer: Lunar and Planetary Science Conference
  • Place of Presentation: 米国・テキサス州
  • Year and Date: 2009-03-15
• [Presentation] イトカワの岩塊にみられる高輝度スポット:形態の分類と岩塊のサイズ分布 (2008)
  • Author(s): 竹内洋人、宮本英昭
  • Organizer: 日本惑星科学会秋期講演会
  • Place of Presentation: 博多
  • Year and Date: 2008-11-01
• [Presentation] 小惑星探査で何を知りたいか-レーダー探査への期待- (2008)
  • Author(s): 春山純一、西堀俊幸、宮本英昭
  • Organizer: シンポジウム「はやぶさ後継機にむけた太陽系小天体の科学」
  • Place of Presentation: JAXA相模原キャンパス
  • Year and Date: 2008-08-28
• [Presentation] 小天体の表層プロセスと内部探査の重要性 (2008)
  • Author(s): 宮本英昭
  • Organizer: シンポジウム「はやぶさ後継機にむけた太陽系小天体の科学」
  • Place of Presentation: JAXA相模原キャンパス
  • Year and Date: 2008-08-27
• [Presentation] Geologic processes on the surface of a small asteroid Itokawa (2008)
  • Author(s): Hirata, N., S.Abe, M.Ishiguro, K.Kitazato, R.Nakamura, H.Miyamoto,, H.Demura, M.Abe, S.Sasaki, S.
  • Organizer: 71st Annual meeting of Meteoritical Society
  • Place of Presentation: 松江
  • Year and Date: 2008-07-30
• [Presentation] 高解像画像に見られるイトカワ上のbright dotの分布 (2008)
  • Author(s): 竹内洋人、宮本英昭
  • Organizer: 日本地球惑星科学連合2008年大会
  • Place of Presentation: 幕張
  • Year and Date: 2008-05-29
• [Remarks] ホームページ等