{
  "abstract": "We apply a two-layer thermophysical model, with water sublimating from below a dust-crust with dynamically varying depth, to simulate the water outgassing rate, dust-ejections, and non-gravitational forces and torques of comet 67P/Churyumov-Gerasimenko. The dust-depth is determined at each time-step by the balance of dehydration and subsurface pressure, leading to alternating ejections and crust build-up. This model is the first stage of implementing a fully coupled activity-fallback model that self-consistently incorporates dust-fallback into the ejection depth calculation, but already a number of conclusions can be drawn from these results. The two-layer model with only dehydration and ejections is able to reproduce much of the Rosetta outgassing, dust-ejection data and non-gravitational dynamics, particularly in the comet’s more primitive southern terrain. Best agreement is found for nucleus material made up of small aggregates (dagg ~ 1 mm) with not-too-high dust-to-ice ratios (δ ~ 2 − 8) and low average strengths (≲ 1 Pa) that decreases with depth. Disagreements between the observations and model are greatest for the northern-facing and dust-covered terrains, suggesting the importance of surface modification by fallback and material processing here, which will be the subject of investigation in the next paper.",
  "abstract_shown": true,
  "affiliations": [
    "Instituto de Astrofísica de Andalucía (CSIC) , Glorieta de la Astronomía s/n. 18008 Granada ,",
    "Institut für Geophysik und Extraterrestrische Physik, Technische Universität Braunschweig , Mendelssohnstr. 3, 38106 Braunschweig ,",
    "Max-Planck-Institut für Sonnensystemforschung , Justus-von-Liebig-Weg 3, 37077, Göttingen ,",
    "Aix Marseille Univ , CNRS, CNES, Laboratoire d’Astrophysique de Marseille, Marseille ,",
    "Brown University Department of Earth, Environmental, and Planetary Sciences, , Providence, RI ,",
    "Physikalisches Institut , Sidlerstr. 5, University of Bern, CH-3012, Bern ,"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 7,
  "authors": [
    {
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        0
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      "name": "N Attree",
      "orcid": "0000-0003-3344-6693"
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    {
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        1,
        2
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      "name": "Y Skorov"
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    {
      "affs": [
        0
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      "name": "P Gutiérrez"
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    {
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        3
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      "name": "O Groussin"
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    {
      "affs": [
        4
      ],
      "name": "A Jindal"
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    {
      "affs": [
        5
      ],
      "name": "R Marschall"
    },
    {
      "affs": [
        4
      ],
      "name": "S P D Birch",
      "orcid": "0000-0002-4578-1694"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/6b8vg16ypgz11.bib",
  "cited_by": 0,
  "doi": "10.1093/mnras/stag1930",
  "fulltext_url": null,
  "id": "6b8vg16ypgz11",
  "issns": [
    "0035-8711",
    "1365-2966"
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  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
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      "openalex",
      "3103|Astro and Planetary Science"
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  "pdf_url": "https://academic.oup.com/mnras/advance-article-pdf/doi/10.1093/mnras/stag1930/71838590/stag1930.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-10",
  "publisher": "Oxford University Press (OUP)",
  "ris": "https://research.draconitic.com/paper/6b8vg16ypgz11.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:17Z",
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      "url": "https://academic.oup.com/mnras/advance-article/doi/10.1093/mnras/stag1930/8907354"
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  "subjects": [
    {
      "field": "astronomy",
      "origin": "openalex:3103|Astro and Planetary Science",
      "subfield": "planetary"
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  ],
  "title": "Towards a coupled activity-fallback model for comets I) 67P/Churyumov-Gerasimenko’s water activity from a microphysics model with dynamic dust-depth",
  "title_text": "Towards a coupled activity-fallback model for comets I) 67P/Churyumov-Gerasimenko’s water activity from a microphysics model with dynamic dust-depth",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:17Z",
  "url": "https://research.draconitic.com/paper/6b8vg16ypgz11",
  "venue": "Monthly Notices of the Royal Astronomical Society",
  "versions": [
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      "doi": "10.48550/arxiv.2610.13230",
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      "relation": "preprint",
      "title": "Towards a coupled activity-fallback model for comets I) 67P/Churyumov-Gerasimenko's water activity from a microphysics model with dynamic dust-depth",
      "venue": "arXiv"
    }
  ]
}