An artificial impact on the asteroid (162173) Ryugu formed a crater in the gravity-dominated regime

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.; Morota, T.; Kameda, S.; Tatsumi, E.; Cho, Y.; Yoshioka, K.; Yokota, Y.; Matsuoka, M.; Yamada, M.; Kouyama, T.; Honda, C.; Tsuda, Y.; Watanabe, S.; Yoshikawa, M.; Tanaka, S.; Terui, F.; Kikuchi, S.; Yamaguchi, T.; Ogawa, N.; Ono, G.; Yoshikawa, K.; Takahashi, T.; Takei, Y.; Fujii, A.; Takeuchi, H.; Yamamoto, Y.; Okada, T.; Hirose, C.; Hosoda, S.; Mori, O.; Shimada, T.; Soldini, S.; Tsukizaki, R.; Iwata, T.; Ozaki, M.; Abe, M.; Namiki, N.; Kitazato, K.; Tachibana, S.; Ikeda, H.; Hirata, N.; Hirata, N.; Noguchi, R.; Miura, A.
Bibliographical reference

Science

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4
2020
Journal
Number of authors
68
IAC number of authors
1
Citations
182
Refereed citations
177
Description
The Hayabusa2 spacecraft investigated the small asteroid Ryugu, which has a rubble-pile structure. We describe an impact experiment on Ryugu using Hayabusa2’s Small Carry-on Impactor. The impact produced an artificial crater with a diameter >10 meters, which has a semicircular shape, an elevated rim, and a central pit. Images of the impact and resulting ejecta were recorded by the Deployable CAMera 3 for >8 minutes, showing the growth of an ejecta curtain (the outer edge of the ejecta) and deposition of ejecta onto the surface. The ejecta curtain was asymmetric and heterogeneous and it never fully detached from the surface. The crater formed in the gravity-dominated regime; in other words, crater growth was limited by gravity not surface strength. We discuss implications for Ryugu’s surface age.
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Minor Bodies of the Solar System
This project studies the physical and compositional properties of the so-called minor bodies of the Solar System, that includes asteroids, icy objects, and comets. Of special interest are the trans-neptunian objects (TNOs), including those considered the most distant objects detected so far (Extreme-TNOs or ETNOs); the comets and the comet-asteroid
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León Cruz