A primordial noble gas component discovered in the Ryugu asteroid and its implications

Alexander B Verchovsky; Feargus A J Abernethy; Mahesh Anand; Ian A Franchi; Monica M Grady; Richard C Greenwood; Simeon J Barber; Martin Suttle; Motoo Ito; Naotaka Tomioka; Masayuki Uesugi; Akira Yamaguchi; Makoto Kimura; Naoya Imae; Naoki Shirai; Takuji Ohigashi; Ming-Chang Liu; Kentaro Uesugi; Aiko Nakato; Kasumi Yogata; Hayato Yuzawa; Yuzuru Karouji; Satoru Nakazawa; Tatsuaki Okada; Takanao Saiki; Satoshi Tanaka; Fuyuto Terui; Makoto Yoshikawa; Akiko Miyazaki; Masahiro Nishimura; Toru Yada; Masanao Abe; Tomohiro Usui; Sen-Ichiro Watanabe; Yuichi Tsuda; Consortium Phase2 curation team Kochi

doi:10.1038/s41467-024-52165-0

A primordial noble gas component discovered in the Ryugu asteroid and its implications

Nat Commun. 2024 Sep 14;15(1):8075. doi: 10.1038/s41467-024-52165-0.

Authors

Alexander B Verchovsky¹, Feargus A J Abernethy², Mahesh Anand², Ian A Franchi², Monica M Grady², Richard C Greenwood², Simeon J Barber², Martin Suttle², Motoo Ito^{3

4}, Naotaka Tomioka³, Masayuki Uesugi⁵, Akira Yamaguchi⁶, Makoto Kimura⁷, Naoya Imae⁸, Naoki Shirai⁹, Takuji Ohigashi^{8

9}, Ming-Chang Liu¹⁰, Kentaro Uesugi⁵, Aiko Nakato^{6

11}, Kasumi Yogata¹¹, Hayato Yuzawa⁸, Yuzuru Karouji¹², Satoru Nakazawa¹¹, Tatsuaki Okada¹¹, Takanao Saiki¹¹, Satoshi Tanaka¹¹, Fuyuto Terui¹¹, Makoto Yoshikawa¹¹, Akiko Miyazaki¹¹, Masahiro Nishimura¹¹, Toru Yada¹¹, Masanao Abe¹¹, Tomohiro Usui¹¹, Sen-Ichiro Watanabe¹³, Yuichi Tsuda^{11

14}; Consortium Phase2 curation team Kochi

Collaborators

Consortium Phase2 curation team Kochi:
Naoya Imae, Naoki Shirai, Kaoki Hirahara, Ikuya Sakurai, Ikuo Okado, Ross Findlay, James A Malley, Xuchao Zhao, Cerdic Pilorget, Jean-Pierre Bebring, Dambien Loizeau, John Carter, Lucie Riu, Tania Le Pivert-Jolivet, Katlyn McCain, Nozomi Matsuda

Affiliations

¹ The Open University, Milton Keynes, UK. [email protected].
² The Open University, Milton Keynes, UK.
³ Kochi Institute for Core Sample Research, X-star, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Nankoku, Kochi, Japan.
⁴ National Graduate Institute for Policy Studies (GRIPS), Nankoku, Kochi, Japan.
⁵ Japan Synchrotron Radiation Research Institute (JASRI/SPring-8), Sayo, Hyogo, Japan.
⁶ National Institute of Polar Research (NIPR), Tachikawa, Tokyo, Japan.
⁷ Faculty of Science, Kanagawa University, Yokohama, Kanagawa, Japan.
⁸ UVSOR Synchrotron Facility, Institute for Molecular Science, Okazaki, Aichi, Japan.
⁹ Institute of Materials Structure Science, High Energy Accelerator Research Organization, Tsukuba, Ibaraki, Japan.
¹⁰ Lawrence Livermore National Laboratory, Livermore, CA, USA.
¹¹ Institute of Space and Astronautical Science (ISAS), Japan Aerospace Exploration Agency (JAXA), Sagamihara, Kanagawa, Japan.
¹² Core Facility Center, Osaka University, 8-1 Mihogaoka, Ibaraki, Osaka, Japan.
¹³ Graduate School of Environmental Studies, Nagoya University, Nagoya, Aichi, Japan.
¹⁴ The Graduate University for Advanced Studies (SOKENDAI), Hayama, Kanagawa, Japan.

Abstract

Ryugu is the C-type asteroid from which material was brought to Earth by the Hayabusa2 mission. A number of individual grains and fine-grained samples analysed so far for noble gases have indicated that solar wind and planetary (known as P1) noble gases are present in Ryugu samples with concentrations higher than those observed in CIs, suggesting the former to be more primitive compared to the latter. Here we present results of analyses of three fine-grained samples from Ryugu, in one of which Xe concentration is an order of magnitude higher than determined so far in other samples from Ryugu. Isotopically, this Xe resembles P1, but with a much stronger isotopic fractionation relative to solar wind and significantly lower ³⁶Ar/¹³²Xe ratio than in P1. This previously unknown primordial noble gas component (here termed P7) provides clues to constrain how the solar composition was fractionated to form the planetary components.