Formation and evolution of carbonaceous asteroid Ryugu: Direct evidence from returned samples

著者: Tomoki Nakamura, Megumi Matsumoto, Kana Amano, Yuma Enokido, M. E. Zolensky, T. Mikouchi, Hidenori Genda, Satoshi Tanaka, M. Yu. Zolotov, Kosuke Kurosawa, Shigeru Wakita, Ryuki Hyodo, Hosei Nagano, D. Nakashima, Yoshio Takahashi, Yuri Fujioka, Mizuha Kikuiri, Eiichi Kagawa, M. Matsuoka, A. J. Brearley, A. Tsuchiyama, Masayuki Uesugi, Junya Matsuno, Yuki Kimura, Masahiko Sato, R. E. Milliken, Eri Tatsumi, Seiji Sugita, T. Hiroi, K. Kitazato, D. E. Brownlee, D. J. Joswiak, Masaki Takahashi, Kazuhiko Ninomiya, Tadayuki Takahashi, Takahito Osawa, Kentaro Terada, Frank E. Brenker, B. J. Tkalcec, László Vincze, R. Brunetto, Alice Aléon‐Toppani, Q. H. S. Chan, Mathieu Roskosz, Jean‐Christophe Viennet, Pierre Beck, E. E. Alp, Tatsuhiro Michikami, Yuuya Nagaashi, Takeshi Tsuji, Yuta Ino, J. Martinez, J. Han, Andrei Dolocan, Robert J. Bodnar, M. Tanaka, Hideto Yoshida, K. Sugiyama, A. J. King, Keisuke Fukushi, Hiroki Suga, Shohei Yamashita, T. Kawai, Kumiko Inoue, Aiko Nakato, T. Noguchi, F. Vilas, Amanda Hendrix, Camilo Jaramillo, D. L. Domingue, G. Domínguez, Z. Gainsforth, C. Engrand, J. Duprat, S. S. Russell, Enrica Bonato, Chi Ma, Tatsuhiko Kawamoto, Takehiko Wada, Sei‐ichiro Watanabe, Rie Endo, Satomi Enju, Lucie Riu, Stefano Rubino, Pieter Tack, Soshi Takeshita, Yasuo Takeichi, Akihisa Takeuchi, Aki Takigawa, D. Takir, Toshiaki Tanigaki, Atsushi Taniguchi, Katsuo Tsukamoto, Takashi Yagi, S. Yamada, Kazuo Yamamoto, Yuichiro Yamashita, Masahiro Yasutake, Kentaro Uesugi, Izumi Umegaki, I. Chiu, Takuya Ishizaki, Shota Okumura, E. Palomba, C. Pilorget, S. Potin, Abdulkareem Alasli, Satoshi Anada, Yui ARAKI, Naoya Sakatani, Cody Schultz, Oki Sekizawa, Scott D. Sitzman, Keisuke Sugiura, Mingqi Sun, E. Dartois, Ella De Pauw, Z. Dionnet, Z. Djouadi, Gerald Falkenberg, Ryohei Fujita, Takeshi Fukuma, I. R. Gearba, Kenji Hagiya, Michael Y. Hu, Takeharu Kato, Taïchi Kawamura, Masao Kimura, M. K. Kubo, F. Langenhorst, C. Lantz, Barbara Lavina, Miles Lindner, Jiyong Zhao, Bart Vekemans, D. Baklouti, Benjamin Bazi, Ferenc Borondics, Shunsaku Nagasawa, Gaku Nishiyama, Kiyofumi Nitta, Jérémie Mathurin, Toru Matsumoto, Itaru Mitsukawa, Hitoshi Miura, Akira Miyake, Yasuhiro Miyake, Hisayoshi Yurimoto, Ryuji Okazaki, Hikaru Yabuta, Hiroshi Naraoka, Kanako Sakamoto, Shogo Tachibana, H. C. Connolly, D. S. Lauretta, Miwa Yoshitake, Makoto Yoshikawa, Kent Yoshikawa, Keisuke Yoshihara, Y. Yokota, Kasumi Yogata, Hajime Yano, Yukio Yamamoto, Daiki Yamamoto, Manabu Yamada, Tetsuya Yamada, Toru Yada, Koji Wada, Tomohiro Usui, Ryudo Tsukizaki, Fuyuto Terui, Hiroshi Takeuchi, Yuto Takei, Ayako Iwamae, Hiromichi Soejima, K. Shirai, Yuri Shimaki, Hiroki Senshu, Hirotaka Sawada, Takanao Saiki, Masanobu Ozaki, Go Ono, Tatsuaki Okada, Naoko Ogawa, Kazunori Ogawa, Rina Noguchi, Hirotomo Noda, Masahiro Nishimura, Noriyuki Namiki, Satoru Nakazawa, Tomokatsu Morota, Akiko Miyazaki, Akira Miura, Yuya Mimasu, Koji Matsumoto, Kazuya Kumagai, Toru Kouyama, Shota Kikuchi, Kosuke Kawahara, Shingo Kameda, Takahiro Iwata, Yoshiaki Ishihara, Masateru Ishiguro, Hitoshi Ikeda, S Hosoda, Rie Honda, Chikatoshi Honda, Yuya Hitomi, Naoyuki Hirata, Naru Hirata, Tasuku Hayashi, Masahiko Hayakawa, Kentaro Hatakeda, Shizuho Furuya, Ryota Fukai, Atsushi Fujii, Yuichiro Cho, Masahiko Arakawa, Masanao Abe, Sei‐ichiro Watanabe, Yuichi Tsuda - Science 2022 被引用: 323

Samples of the carbonaceous asteroid Ryugu were brought to Earth by the Hayabusa2 spacecraft. We analyzed 17 Ryugu samples measuring 1 to 8 millimeters. Carbon dioxide-bearing water inclusions are present within a pyrrhotite crystal, indicating that Ryugu's parent asteroid formed in the outer Solar System. The samples contain low abundances of materials that formed at high temperatures, such as chondrules and calcium- and aluminum-rich inclusions. The samples are rich in phyllosilicates and carbonates, which formed through aqueous alteration reactions at low temperature, high pH, and water/rock ratios of <1 (by mass). Less altered fragments contain olivine, pyroxene, amorphous silicates, calcite, and phosphide. Numerical simulations, based on the mineralogical and physical properties of the samples, indicate that Ryugu's parent body formed ~2 million years after the beginning of Solar System formation.