TY - JOUR

T1 - Hydrogen Isotopic Composition of Hydrous Minerals in Asteroid Ryugu

AU - Piani, Laurette

AU - Nagashima, Kazuhide

AU - Kawasaki, Noriyuki

AU - Sakamoto, Naoya

AU - Bajo, Ken-ichi

AU - Abe, Yoshinari

AU - Aléon, Jérôme

AU - Alexander, Conel M. O'D.

AU - Amari, Sachiko

AU - Amelin, Yuri

AU - Bizzarro, Martin

AU - Bouvier, Audrey

AU - Carlson, Richard W.

AU - Chaussidon, Marc

AU - Choi, Byeon-Gak

AU - Dauphas, Nicolas

AU - Davis, Andrew M.

AU - Di Rocco, Tommaso

AU - Fujiya, Wataru

AU - Fukai, Ryota

AU - Gautam, Ikshu

AU - Haba, Makiko K.

AU - Hibiya, Yuki

AU - Hidaka, Hiroshi

AU - Homma, Hisashi

AU - Hoppe, Peter

AU - Huss, Gary R.

AU - Ichida, Kiyohiro

AU - Iizuka, Tsuyoshi

AU - Ireland, Trevor R.

AU - Ishikawa, Akira

AU - Itoh, Shoichi

AU - Kita, Noriko T.

AU - Kitajima, Kouki

AU - Kleine, Thorsten

AU - Komatani, Shintaro

AU - Krot, Alexander N.

AU - Liu, Ming-Chang

AU - Masuda, Yuki

AU - McKeegan, Kevin D.

AU - Morita, Mayu

AU - Motomura, Kazuko

AU - Moynier, Frédéric

AU - Nakai, Izumi

AU - Nguyen, Ann

AU - Nittler, Larry

AU - Onose, Morihiko

AU - Pack, Andreas

AU - Park, Changkun

AU - Qin, Liping

AU - Russell, Sara S.

AU - Schönbächler, Maria

AU - Tafla, Lauren

AU - Tang, Haolan

AU - Terada, Kentaro

AU - Terada, Yasuko

AU - Usui, Tomohiro

AU - Wada, Sohei

AU - Wadhwa, Meenakshi

AU - Walker, Richard J.

AU - Yamashita, Katsuyuki

AU - Yin, Qing-Zhu

AU - Yokoyama, Tetsuya

AU - Yoneda, Shigekazu

AU - Young, Edward D.

AU - Yui, Hiroharu

AU - Zhang, Ai-Cheng

AU - Nakamura, Tomoki

AU - Naraoka, Hiroshi

AU - Okazaki, Ryuji

AU - Sakamoto, Kanako

AU - Yabuta, Hikaru

AU - Abe, Masanao

AU - Miyazaki, Akiko

AU - Nakato, Aiko

AU - Nishimura, Masahiro

AU - Okada, Tatsuaki

AU - Yada, Toru

AU - Yogata, Kasumi

AU - Nakazawa, Satoru

AU - Saiki, Takanao

AU - Tanaka, Satoshi

AU - Terui, Fuyuto

AU - Tsuda, Yuichi

AU - Watanabe, Sei-ichiro

AU - Yoshikawa, Makoto

AU - Tachibana, Shogo

AU - Yurimoto, Hisayoshi

N1 - Publisher Copyright: © 2023. The Author(s). Published by the American Astronomical Society.

PY - 2023

Y1 - 2023

N2 - 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.

AB - 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.

U2 - 10.3847/2041-8213/acc393

DO - 10.3847/2041-8213/acc393

M3 - Journal article

AN - SCOPUS:85152566952

VL - 946

JO - The Astrophysical Journal Letters

JF - The Astrophysical Journal Letters

SN - 2041-8205

IS - 2

M1 - L43

ER -