Hydrogen Isotopic Composition of Hydrous Minerals in Asteroid Ryugu

Piani, Laurette and Nagashima, Kazuhide and Kawasaki, Noriyuki and Sakamoto, Naoya and Bajo, Ken-ichi and Abe, Yoshinari and Aléon, Jérôme and O’D. Alexander, Conel M. and Amari, Sachiko and Amelin, Yuri and Bizzarro, Martin and Bouvier, Audrey and Carlson, Richard W. and Chaussidon, Marc and Choi, Byeon-Gak and Dauphas, Nicolas and Davis, Andrew M. and Di Rocco, Tommaso and Fujiya, Wataru and Fukai, Ryota and Gautam, Ikshu and Haba, Makiko K. and Hibiya, Yuki and Hidaka, Hiroshi and Homma, Hisashi and Hoppe, Peter and Huss, Gary R. and Ichida, Kiyohiro and Iizuka, Tsuyoshi and Ireland, Trevor R. and Ishikawa, Akira and Itoh, Shoichi and Kita, Noriko T. and Kitajima, Kouki and Kleine, Thorsten and Komatani, Shintaro and Krot, Alexander N. and Liu, Ming-Chang and Masuda, Yuki and McKeegan, Kevin D. and Morita, Mayu and Motomura, Kazuko and Moynier, Frédéric and Nakai, Izumi and Nguyen, Ann and Nittler, Larry and Onose, Morihiko and Pack, Andreas and Park, Changkun and Qin, Liping and Russell, Sara S. and Schönbächler, Maria and Tafla, Lauren and Tang, Haolan and Terada, Kentaro and Terada, Yasuko and Usui, Tomohiro and Wada, Sohei and Wadhwa, Meenakshi and Walker, Richard J. and Yamashita, Katsuyuki and Yin, Qing-Zhu and Yokoyama, Tetsuya and Yoneda, Shigekazu and Young, Edward D. and Yui, Hiroharu and Zhang, Ai-Cheng and Nakamura, Tomoki and Naraoka, Hiroshi and Okazaki, Ryuji and Sakamoto, Kanako and Yabuta, Hikaru and Abe, Masanao and Miyazaki, Akiko and Nakato, Aiko and Nishimura, Masahiro and Okada, Tatsuaki and Yada, Toru and Yogata, Kasumi and Nakazawa, Satoru and Saiki, Takanao and Tanaka, Satoshi and Terui, Fuyuto and Tsuda, Yuichi and Watanabe, Sei-ichiro and Yoshikawa, Makoto and Tachibana, Shogo and Yurimoto, Hisayoshi (2023) Hydrogen Isotopic Composition of Hydrous Minerals in Asteroid Ryugu. The Astrophysical Journal Letters, 946 (2). L43. ISSN 2041-8205

[thumbnail of 2.pdf] Text
2.pdf - Published Version
Download (2MB)

Abstract

Rock fragments of the Cb-type asteroid Ryugu returned to Earth by the JAXA Hayabusa2 mission share mineralogical, chemical, and isotopic properties with the Ivuna-type (CI) carbonaceous chondrites. Similar to CI chondrites, these fragments underwent extensive aqueous alteration and consist predominantly of hydrous minerals likely formed in the presence of liquid water on the Ryugu parent asteroid. Here we present an in situ analytical survey performed by secondary ion mass spectrometry from which we have estimated the D/H ratio of Ryugu's hydrous minerals, D/HRyugu, to be [165 ± 19] × 10−6, which corresponds to δDRyugu = +59 ± 121‰ (2σ). The hydrous mineral D/HRyugu's values for the two sampling sites on Ryugu are similar; they are also similar to the estimated D/H ratio of hydrous minerals in the CI chondrites Orgueil and Alais. This result reinforces a link between Ryugu and CI chondrites and an inference that Ryugu's samples, which avoided terrestrial contamination, are our best proxy to estimate the composition of water at the origin of hydrous minerals in CI-like material. Based on this data and recent literature studies, the contribution of CI chondrites to the hydrogen of Earth's surficial reservoirs is evaluated to be ∼3%. We conclude that the water responsible for the alteration of Ryugu's rocks was derived from water ice precursors inherited from the interstellar medium; the ice partially re-equilibrated its hydrogen with the nebular H2 before being accreted on the Ryugu's parent asteroid.

Item Type: Article
Subjects: Eprints AP open Archive > Physics and Astronomy
Depositing User: Unnamed user with email admin@eprints.apopenarchive.com
Date Deposited: 04 May 2023 08:25
Last Modified: 15 Sep 2023 04:05
URI: http://asian.go4sending.com/id/eprint/109

Actions (login required)

View Item
View Item