[P-PS04] Regolith Science

[PPS04-04] Space impact experiment on Ryugu: Pattern of ejecta curtain and the properties of particles in surface and subsurface layers

★Invited Papers

*門野 敏彦¹、荒川 政彦²、本田 理恵³、石橋 高⁴、小川 和律⁵、坂谷 尚哉⁵、嶌生 有理⁵、杉田 精司⁶、和田 浩二⁴ (1.産業医科大学医学部、2.神戸大学大学院理学研究科、3.高知大学自然科学系理工学部門、4.千葉工業大学惑星探査研究センター、5.宇宙科学研究所、6.東京大学大学院理学系研究科)

キーワード：はやぶさ２、宇宙衝突実験、衝突放出物

Space-impact experiment was performed on the surface of the C-type asteroid 162173Ryugu using an instrument called the Small Carry-on Impactor (SCI), carried by JAXA spacecraft Hayabusa2. One advantage of the Hayabusa2 for space-impact experiments was the use of a small satellite separated from the spacecraft, the Deployable CAMera-3 (DCAM3), using which we observed the evolution of the ejecta curtain by the SCI impact in situ. In this presentation, based on the patterns of the ejecta curtain, we evaluated the properties of boulders and particles in the surface and subsurface of Ryugu. We found that the boulders on the surface layer had a strength of ~ a few hundred kPa. Furthermore, the particles in the curtain had a characteristic size of a few cm with the maximum size of several decimeters, mainly originated from the subsurface layer. We propose some processes to realize these features.