{
  "abstract": "Amino acid enantiomeric excess (EE) is a potential biosignature, but its measurement requires sufficient surviving material as well as preserved chirality. We derive a criterion that separates abundance-limited from racemization-limited preservation and apply it to the Mars Organic Molecule Analyzer (MOMA) on the ExoMars Rosalind Franklin rover. The model combines cosmic-ray and radiogenic doses with laboratory destruction kinetics and assumed ratios of interconversion to destruction rates. For an initially homochiral population of 1000~ppmw, the surviving EE is 58\\% or 25\\% when the total abundance reaches 1~ppmw for rate ratios of 0.04 or 0.10, respectively. This abundance criterion does not ensure that both enantiomers can be quantified. Applying provisional estimates of 1~ppmw per enantiomer and 10\\% EE, serine at 2~m requires initial concentrations of 340 and 960~ppmw after cosmic-ray exposures of $10^{7}$ and $10^{8}$~yr, respectively, under transferred fused-silica--perchlorate kinetics and a 1.57-MGy radiogenic dose. These concentrations exceed measured meteoritic serine abundances, but do not predict the initial Oxia inventory. For organics retained in a closed host since deposition 3.9~Ga ago, the modeled radiogenic dose is 1.6--5.6~MGy across the adopted compositions. In the lower-dose case, drilling to 2~m reduces the total dose by only a factor of 1.5 after $10^{7}$~yr. The boundaries depend on mineral kinetics and organic residence time; they distinguish preserved chirality from a measurable excess.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.17931",
  "author_total": 1,
  "authors": [
    {
      "name": "Dimitra Atri"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/755xph702gbdw.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.17931",
  "fulltext_url": null,
  "id": "755xph702gbdw",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.17931",
  "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"
    ],
    [
      "arxiv",
      "physics.space-ph"
    ],
    [
      "openalex",
      "3103|Planetary Science and Exploration"
    ]
  ],
  "openalex": "W7221798532",
  "pdf_url": "https://arxiv.org/pdf/2610.17931",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-13",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/755xph702gbdw.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:29:11Z",
      "native_id": "2610.17931",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.17931"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.IM",
      "subfield": "instrumentation-methods"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.EP",
      "subfield": "planetary"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:physics.space-ph",
      "subfield": "stellar"
    }
  ],
  "title": "Radiation limits on amino acid preservation and chiral measurement at Oxia Planum",
  "title_text": "Radiation limits on amino acid preservation and chiral measurement at Oxia Planum",
  "type": "preprint",
  "updated_at": "2026-10-30T12:29:11Z",
  "url": "https://research.draconitic.com/paper/755xph702gbdw",
  "venue": "arXiv",
  "versions": []
}