{
  "abstract": "The parent body of the C-type asteroid Ryugu experienced aqueous alteration. The past aqueous environments have been reconstructed using mineralogies and geochemical modeling, often assuming Na-Cl-rich fluid compositions. Here, we reconstruct Ryugu's aqueous environment using chemical equilibrium modeling constrained by Electron Probe Microanalyzer (EPMA) and X-ray absorption near-edge structure spectroscopy. Our results suggest that Ryugu water possessed lower salinity than previously estimated and was highly reducing (Eh: -0.5 to -0.8 V) and strongly alkaline (pH: 10.3 to 11.5) conditions conducive to prebiotic organic reactions. The inferred high hydrogen fugacity, lack of NaCl, and low salinity recorded in Ryugu sample suggest that aqueous alteration occurred beneath a surface ice layer, with subsequent ice sublimation driving water loss. These findings refine our understanding of C-type asteroids evolution and the quantity and nature of water delivered to the early Earth.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": "research article",
  "arxiv": null,
  "author_total": 23,
  "authors": [
    {
      "name": "Takahiro Kawai"
    },
    {
      "name": "Keisuke Fukushi",
      "orcid": "0000-0003-0398-8950"
    },
    {
      "name": "Tomohiro Ohno"
    },
    {
      "name": "Hiroki Suga"
    },
    {
      "name": "Masayuki Uesugi",
      "orcid": "0000-0001-6261-9034"
    },
    {
      "name": "Ayu Takemoto"
    },
    {
      "name": "Akiko Yamaguchi",
      "orcid": "0000-0001-6235-3600"
    },
    {
      "name": "Takaaki Itai"
    },
    {
      "name": "Yuta Ijichi",
      "orcid": "0009-0005-8079-0317"
    },
    {
      "name": "Shohei Yamashita"
    },
    {
      "name": "Yasuhiro Niwa",
      "orcid": "0000-0001-5808-5594"
    },
    {
      "name": "Ryoichi Nakada",
      "orcid": "0000-0002-2684-3837"
    },
    {
      "name": "Mizuho Koike"
    },
    {
      "name": "Hideto Yoshida"
    },
    {
      "name": "Masaki Oura",
      "orcid": "0000-0002-9999-5612"
    },
    {
      "name": "Megumi Matsumoto",
      "orcid": "0000-0001-6630-6369"
    },
    {
      "name": "Tomohiro Usui"
    },
    {
      "name": "Yoko Kebukawa",
      "orcid": "0000-0001-8430-3612"
    },
    {
      "name": "Takazo Shibuya",
      "orcid": "0000-0002-1289-1328"
    },
    {
      "name": "Shogo Tachibana",
      "orcid": "0000-0002-4603-9440"
    },
    {
      "name": "Yasuhito Sekine",
      "orcid": "0000-0002-3544-3632"
    },
    {
      "name": "Tomoki Nakamura"
    },
    {
      "name": "Yoshio Takahashi",
      "orcid": "0000-0001-7860-2341"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/2znv170ebv9bv.bib",
  "cited_by": 0,
  "doi": "10.1038/s41467-026-78348-5",
  "fulltext_url": "https://europepmc.org/articles/PMC13675196",
  "id": "2znv170ebv9bv",
  "issns": [
    "2041-1723"
  ],
  "landing_url": "https://www.nature.com/articles/s41467-026-78348-5",
  "language": "eng",
  "licence": "CC-BY-NC-ND-4.0",
  "licence_label": "CC BY-NC-ND 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nc-nd/4.0",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "3103|Astro and Planetary Science"
    ]
  ],
  "openalex": "W7222510089",
  "pdf_url": "https://www.nature.com/articles/s41467-026-78348-5.pdf",
  "pmcid": "PMC13675196",
  "pmid": "42888181",
  "published": "2026-10-16",
  "publisher": "Springer Science and Business Media LLC",
  "ris": "https://research.draconitic.com/paper/2znv170ebv9bv.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:38Z",
      "native_id": "10.1038/s41467-026-78348-5",
      "source": "crossref",
      "url": "https://www.nature.com/articles/s41467-026-78348-5"
    },
    {
      "first_seen": "2026-10-30T12:18:46Z",
      "native_id": "MED:42888181",
      "source": "europepmc",
      "url": "https://europepmc.org/article/MED/42888181"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "openalex:3103|Astro and Planetary Science",
      "subfield": "planetary"
    }
  ],
  "title": "Reconstructing the aqueous environment of the Ryugu parent body through the speciation of multiple elements",
  "title_text": "Reconstructing the aqueous environment of the Ryugu parent body through the speciation of multiple elements",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:46Z",
  "url": "https://research.draconitic.com/paper/2znv170ebv9bv",
  "venue": "Nature Communications",
  "versions": []
}