Japan Geoscience Union Meeting 2023

Presentation information

[E] Oral

P (Space and Planetary Sciences ) » P-PS Planetary Sciences

[P-PS03] Small Solar System Bodies: New perspectives on the origin and evolution of the Solar System

Wed. May 24, 2023 10:45 AM - 12:15 PM 301A (International Conference Hall, Makuhari Messe)

convener:Tatsuaki Okada(Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency), Fumi Yoshida(University of Occupational and Environmental Health, Japan), Sota Arakawa(Japan Agency for Marine-Earth Science and Technology), Ryota Fukai(Japan Aerospace Exploration Agency), Chairperson:Ryota Fukai(Japan Aerospace Exploration Agency), Sota Arakawa(Japan Agency for Marine-Earth Science and Technology), Tatsuaki Okada(Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency), Fumi Yoshida(University of Occupational and Environmental Health, Japan)


10:45 AM - 11:00 AM

[PPS03-06] Current status of Ryugu sample curation and preparation for OSIRIS-REx-returned sample curation

*Toru Yada1, Masanao Abe1, Masahiro Nishimura1, Tatsuaki Okada1, Ryota Fukai1, Sakamoto Kanako1, Kasumi Yogata1, Kentaro Hatakeda1,2, Akiko Miyazaki1, Kana Nagashima1, Rui Tahara1, Rei Kanemaru1, Arisa Nakano1, Tomoko Ojima1, Yuya Hitomi1,2, Yuka Sugiyama1, Kazuya Kumagai1,2, Hiromichi Soejima1,2, Takuya Ishizaki1, Soichiro Furukawa3, Haruna Sugahara1, Shino Suzuki1, Seiji Sugita3, Yuichiro Cho3, Koki Yumoto3, Yuna Yabe3, Shoki Mori3, Keisuke Furuichi3, Yuta Aikyo3, Jean-Pierre Bibring4, Cedric Pilorget4, Rosario Brunetto4, Lucie Riu4, Damien Loizeau4, Lionel Lourit4, Tania Le Pivert-Jolivet4, Cateline Lantz4, Vincent Hamm4, Guillaume Lequertier4, John Carter4, Tomohiro Usui1, Masaki Fujimoto1 (1.Japan Aerospace Exploration Agency, 2.Marine Works Japan, 3.University of Tokyo, 4.Institut d'Astrophysique Spatiale, Université Paris-Saclay)

Keywords:sample return, curation, Hayabusa2, Ryugu, C-type asteroid, OSIRIS-REx

Since C-type near-Earth asteroid (NEA) Ryugu samples returned by Hayabusa2 in Dec 2020, initial descriptions of bulk samples have been conducted, including optical observations, weight measurements, an FT-IR analyses, an infrared imager MicrOmega analyses, and a visible spectral measurement. These analyses revealed that the Ryugu samples are composed mainly of hydrous minerals and contain carbonates and organics and are most similar to CI chondrites [1,2]. Nearly 800 individual grains have been picked up so far for initial descriptions including the optical microscope observation and the weight measurements. Subsequently, the FT-IR, the MicrOmega, and the visible spectra analyses for the newly-described grains were followed. Parallel to the initial descriptions at our curation facility, Ryugu samples were distributed to initial analysis and phase2 curation teams in June 2021. These teams revealed that Ryugu samples were most similar to CI chondrites in chemistry and mineralogy with the exceptions of several features. These include that the Ryugu samples contain less water and heterogeneously distributed insoluble organic matters combined with phyllosilicates, and have petrological features such as presences of chips of chondrules and Ca- and Al-rich inclusions [3-7]. Ryugu samples have been distributed to selected principal investigators (PIs) of the Announcement of Opportunity (AO). In the AO1 announced in Jan 2021, 40 proposals were selected for samples distributions in June 2020 and the samples have been distributed at the end of 2022. In the AO2 announced in June 2022, 38 proposals were selected in Jan 2023 and we started distributing samples to the selected PIs in this Feb. AO3 has been announced recently, and its result will be announced this summer.
The OSIRIS-REx, the asteroid explorer by NASA, will return samples to the Earth from the B-type NEA Bennu on Sep. 23, 2023. Based on the memorandum of understanding (MOU) between JAXA and NASA, JAXA shared 10 wt% of Ryugu samples with NASA in Dec 2021, and in return NASA will provide 0.5 wt% of returned Bennu samples with JAXA. As the Bennu samples recovered in the sample canister of the OSIRIS-REx are estimated to be 250±101 g [8], JAXA will receive 0.5 wt% of returned Bennu samples (estimated to be 1.25±0.5 g) within a year after their return to the Earth. Construction of a new clean room was completed last Sep, and new clean chambers for handling and preserving allocated Bennu samples will be installed in the clean room this year. Instruments for initial descriptions are under development, and will be ready to use this year. After receiving the allocated Bennu samples, we plan to perform the preliminary examinations of the samples and upload the preliminary data in a database system, similar to the Ryugu samples. We also plan to announce the AO for the Bennu samples, and call for proposals that mainly focused on comparative studies between the Bennu and Ryugu samples.
References: [1] Yada T. et al. (2022) Nat. Astron. 6, 214. [2] Pilorget C. et al. (2022) Nat. Astron. 6, 221. [3] Nakamura E. et al. (2022) Proc. Japan Acad. B 98, 227. [4] Yokoyama T. et al. (2022) Science, DOI: 10.1126/science.abn7850. [5] Ito M. et al. (2022) Nat. Astron. 6, 1163. [6] Nakamura T. et al. (2022) Science, DOI: 10.1126/science.abn8671. [7] Noguchi T. et al. (2022) Nat. Astron. https://doi.org/10.1038/s41550-022-01841-6. [8] Lauretta D. S. et al. (2022) Science 377, 285.