Surface morphological features of boulders on Asteroid 25143 Itokawa

Takaaki Noguchi, Akira Tsuchiyama, Naru Hirata, Hirohide Demura, Ryosuke Nakamura, Hideaki Miyamoto, Hajime Yano, Tomoki Nakamura, Jun Saito, Sho Sasaki, Tatsuaki Hashimoto, Takashi Kubota, Masateru Ishiguro, Michael E. Zolensky

研究成果: Contribution to journalArticle

19 引用 (Scopus)

抜粋

On the sub-kilometer S-type asteroid, 25143 Itokawa, some boulders on rough terrains seem to be exposed without any powdery material covering. Based on surface morphological features, there are two major types of boulders: one has rounded edges and corners (rounded boulders), while the other has angular edges and corners (angular boulders). The surface features of the rounded boulders suggest that they have hardness heterogeneity and that some may be breccias. The angular boulders appear to be more resistant to impact disruption than the rounded ones, which may be due to a difference in lithology. The major constituents of Itokawa may be LL chondrite-like brecciated lithology (rounded boulders) along with a remarkable number of boulders suggesting that lithology is atypical among LL chondrites (angular boulders). Some of both types of boulders contain intersecting and stepped planar foliations. Comparison with meteorite ALH76009 suggests that the planar foliations may be marks where rocks were torn apart. As lithified breccias cannot be formed on present-day sub-kilometer-sized Itokawa, it is reasonable that boulders with various lithologies on Itokawa were formed on its large ancestor(s). The rubble-pile structure of Itokawa suggested by its low density (∼1.9 g/cm3) indicates that boulders on Itokawa are reassembled fragments formed by catastrophic disruption of large ancestor(s).

元の言語英語
ページ(範囲)319-326
ページ数8
ジャーナルIcarus
206
発行部数1
DOI
出版物ステータス出版済み - 3 1 2010
外部発表Yes

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science

フィンガープリント Surface morphological features of boulders on Asteroid 25143 Itokawa' の研究トピックを掘り下げます。これらはともに一意のフィンガープリントを構成します。

  • これを引用

    Noguchi, T., Tsuchiyama, A., Hirata, N., Demura, H., Nakamura, R., Miyamoto, H., Yano, H., Nakamura, T., Saito, J., Sasaki, S., Hashimoto, T., Kubota, T., Ishiguro, M., & Zolensky, M. E. (2010). Surface morphological features of boulders on Asteroid 25143 Itokawa. Icarus, 206(1), 319-326. https://doi.org/10.1016/j.icarus.2009.09.002