{
  "abstract": "Tycho (43.37°S, 348.68°E) is a ∼100 Myr old lunar impact crater distinguished by an extensive ray system populated by numerous secondary craters. While proximal secondaries display elongated and asymmetric crater morphologies, distal secondaries can resemble primary craters, increasing the risk of misclassification in crater-based age determinations. Here, we use radar observations of bright, extended, asymmetric ejecta deposits that point in the downrange direction from Tycho to identify and characterize potential Tycho-related secondary craters. We identify 663 such craters along Tycho’s rays and review additional morphometric evidence of their secondary nature. Although some of these craters appear in linear chains or clustered groups, others are isolated and would otherwise be difficult to recognize as secondaries. The radar-bright asymmetric ejecta generally align with ray orientations, although ∼10% of craters show ejecta patterns likely influenced by local slopes. Radar backscatter from the ejecta is enhanced in depolarized and even-bounce scattering, indicative of rough terrains. Inspection of Narrow Angle Camera and ShadowCam images, though, indicates little to no contribution by surface meter-scale boulders. As such, these observations suggest that scattering may be dominated by subsurface structural heterogeneity or small-scale roughness below the image resolution. Similar radar-bright asymmetric ejecta are also observed around other large rayed craters, including Byrgius A (25.621°S, 62.659°E), Glushko (9.221°N, 76.389°E), and Kepler (9.724°N, 41.54°E), spanning a range of ages and suggesting long-term preservation of wavelength-scale complexity. These results demonstrate that radar observations provide a robust means of identifying distal secondary craters and characterizing ejecta emplacement processes.",
  "abstract_shown": true,
  "affiliations": [
    "Purdue University",
    "Johns Hopkins Applied Physics Laboratory",
    "CRESST-II University of Maryland",
    "Planetary Science Institute"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 9,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Santa L. Pérez-Cortés",
      "orcid": "0000-0002-6268-0430"
    },
    {
      "affs": [
        1
      ],
      "name": "Edgard G. Rivera-Valentín",
      "orcid": "0000-0002-4042-003X"
    },
    {
      "affs": [
        2
      ],
      "name": "Caitlin J. Ahrens",
      "orcid": "0000-0003-1574-112X"
    },
    {
      "affs": [
        0
      ],
      "name": "Ali M. Bramson",
      "orcid": "0000-0003-4903-0916"
    },
    {
      "affs": [
        1
      ],
      "name": "Caleb I. Fassett",
      "orcid": "0000-0001-9155-3804"
    },
    {
      "affs": [
        2
      ],
      "name": "Cole A. Nypaver",
      "orcid": "0000-0002-3885-7574"
    },
    {
      "affs": [
        3
      ],
      "name": "Gareth Morgan",
      "orcid": "0000-0002-9513-8736"
    },
    {
      "affs": [
        1
      ],
      "name": "G. Wesley Patterson",
      "orcid": "0000-0003-4787-3899"
    },
    {
      "affs": [
        1
      ],
      "name": "Tyler M. Powell",
      "orcid": "0000-0003-3676-6561"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/f8aczmnf6203t.bib",
  "cited_by": 0,
  "doi": "10.3847/psj/aea98b",
  "fulltext_url": null,
  "id": "f8aczmnf6203t",
  "issns": [
    "2632-3338"
  ],
  "landing_url": "https://iopscience.iop.org/article/10.3847/PSJ/aea98b",
  "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": [
    [
      "openalex",
      "3103|Planetary Science and Exploration"
    ]
  ],
  "openalex": "W7221153156",
  "pdf_url": "https://iopscience.iop.org/article/10.3847/PSJ/aea98b/pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-09",
  "publisher": "American Astronomical Society",
  "ris": "https://research.draconitic.com/paper/f8aczmnf6203t.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:16Z",
      "native_id": "10.3847/psj/aea98b",
      "source": "crossref",
      "url": "https://iopscience.iop.org/article/10.3847/PSJ/aea98b"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "openalex:3103|Planetary Science and Exploration",
      "subfield": "planetary"
    }
  ],
  "title": "Radar Identification and Geomorphic Characterization of Distal Tycho Secondary Craters",
  "title_text": "Radar Identification and Geomorphic Characterization of Distal Tycho Secondary Craters",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:16Z",
  "url": "https://research.draconitic.com/paper/f8aczmnf6203t",
  "venue": "The Planetary Science Journal",
  "versions": []
}