{
  "abstract": "The 1976 Viking Carbon Assimilation-Pyrolytic Release (CAPyR) experiment tested whether carbon from $^{14}$CO$_2$ and $^{14}$CO entered Martian soil during a 120-hour incubation in a form retained during a 120 $^\\circ$C purge but released by pyrolysis at 635 $^\\circ$C. Untrapped radioactivity was measured as Peak 1; material retained in an organic vapor trap was oxidized and measured as Peak 2. Net Peak 2 was intended to represent synthesized reduced organic carbon. Seven of nine usable incubations at Chryse and Utopia Planitia yielded significant net Peak 2 signals, including the dark U1 run. An underreported Viking Lander 2 gas leak introduces uncertainty into U1-U3. The C1 signal corresponds to approximately 10 or 30 pmol of carbon, assuming derivation entirely from CO or CO$_2$, respectively. We reassess these results in light of the possible presence of perchlorate salts in Viking soils. Oxidation of fixed organic radiocarbon during pyrolysis could have shifted label from Peak 2 to Peak 1, a perchlorate-specific effect not considered in previous CAPyR analyses. Hubbard's (1979) mineral-substrate experiments produced abiotic Peak 2 signals without reproducing the heat sensitivity. No demonstrated abiotic mechanism has reproduced all CAPyR observations under Mars-relevant conditions. The observations remain consistent with a biological carbon-assimilation system whose relevant activity survives C5's 120 $^\\circ$C/90 $^\\circ$C pretreatment but is strongly impaired by C2's 175 $^\\circ$C pretreatment. Together with the Labeled Release experiment, CAPyR suggests oxidative and reductive chemistry in separate aliquots from common Martian soil acquisitions. Metabolically active life combines these processes; a quantitative abiotic explanation of their combined heat-labile response patterns remains to be demonstrated.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.30368",
  "author_total": 3,
  "authors": [
    {
      "name": "Jan Spacek"
    },
    {
      "name": "Clay A. Abraham"
    },
    {
      "name": "Steven A. Benner"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/6fhxjhq8c8e14.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.30368",
  "fulltext_url": null,
  "id": "6fhxjhq8c8e14",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.30368",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.EP"
    ],
    [
      "arxiv",
      "astro-ph.IM"
    ],
    [
      "openalex",
      "3103|Planetary Science and Exploration"
    ]
  ],
  "openalex": "W7223363976",
  "pdf_url": "https://arxiv.org/pdf/2610.30368",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-21",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/6fhxjhq8c8e14.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:34:34Z",
      "native_id": "2610.30368",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.30368"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.IM",
      "subfield": "instrumentation-methods"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.EP",
      "subfield": "planetary"
    }
  ],
  "title": "A Technical Reanalysis of the Viking Carbon Assimilation-Pyrolytic Release Experiment",
  "title_text": "A Technical Reanalysis of the Viking Carbon Assimilation-Pyrolytic Release Experiment",
  "type": "preprint",
  "updated_at": "2026-10-30T12:34:34Z",
  "url": "https://research.draconitic.com/paper/6fhxjhq8c8e14",
  "venue": "arXiv",
  "versions": []
}