Statistical Analysis of Lunar Impact Flashes
Abstract
Over 850 lunar impact flashes (LIFs) have been reported in the literature and online databases by a wide range of observational campaigns and amateur astronomers [1, 2, 3, 4]. The introduction of PyNAPLE [5], a software package developed to identify craters formed by LIFs, enabled a revised calculation of the luminous efficiency [6]. This parameter is fundamental to LIF studies, as it quantifies the proportion of an impactor’s kinetic energy that is converted into observable light. Consequently, any revision to the luminous efficiency has significant implications for subsequent derived parameters. Here, we revisit all previously reported LIFs using the updated luminous efficiency and expand the dataset to include all additional events recorded to date. Using meteoroid stream determination software [7], we identify the likely parent stream(s) of the impactors, from which we derive properties including impact velocity, impact angle, and density. For flashes observed in multiple wavelength bands, we determine the blackbody temperature of the emission, while for events persisting over multiple frames, we examine the temperature evolution throughout the flash duration. We additionally estimate the diameters of the resulting craters, providing constraints to support future crater searches with tools such as PyNAPLE. The revised luminous efficiency is larger than values previously adopted, meaning that a given impact generates more observable light and therefore corresponds to a smaller impactor than earlier estimates implied. This may account for the difficulty in detecting LIF-associated craters with PyNAPLE, as the craters produced by the faintest observable flashes are comparable to, or smaller than, the pixel scale of the Lunar Reconnaissance Orbiter Narrow Angle Camera (~0.5 m/px). We present the outcomes of these updated calculations along with revised statistical properties of the dataset, including the size–frequency distribution of the observed impacts. References1. Suggs R. M., Moser D. E., Cooke W. J., Suggs R. J., 2014, Icarus, 238, 232. Avdellidou C., et al., 2021, Planet. Space Sci., 200, 1052013. Sheward D., Delbo M., Avdellidou C., Cook A., Lognonné P., 2025, A&A,699, L34. Liakos A., Bonanos A. Z., Xilouris E. M., Koschny D., Bellas-Velidis I., Boumis P., Maroussis A., Moissl R., 2024, A&A, 687, A145. Sheward D., Avdellidou C., Cook A., Sefton-Nash E., Delbo M., Cantarella, B., Zanatta L., 2022, MNRAS, 514, 43206. Sheward D., Delbo M., Avdellidou C., Cook A., Lognonné P., 2025, A&A, 699, L37. Avdellidou C., Vaubaillon J., 2019, MNRAS, 484, 5212
| Authors: | ; ; |
|---|---|
| Publication date: | 02/07/2026 |
| Document type: | Conference abstract |
| DOI: | 10.5194/epsc2026-1021 |
| Open access: | Open access Gold: open access journal – Open access full text (license: CC-BY, accepted version (post-print)) |
| Subjects: |
Astro and Planetary Science
(Physical Sciences > Physics and Astronomy > Astronomy and Astrophysics)
Planetary Science and Exploration
(Physical Sciences > Physics and Astronomy > Astronomy and Astrophysics)
Space Satellite Systems and Control
(Physical Sciences > Engineering > Aerospace Engineering)
|
| Identifiers: | OpenAlex W7167047227 |
Central index data: OpenAlex (CC0 license).
Full central index record (JSON) from api.openalex.org/works/W7167047227
{
"abstract (reconstructed from abstract_inverted_index)": "Over 850 lunar impact flashes (LIFs) have been reported in the literature and online databases by a wide range of observational campaigns and amateur astronomers [1, 2, 3, 4]. The introduction of PyNAPLE [5], a software package developed to identify craters formed by LIFs, enabled a revised calculation of the luminous efficiency [6]. This parameter is fundamental to LIF studies, as it quantifies the proportion of an impactor’s kinetic energy that is converted into observable light. Consequently, any revision to the luminous efficiency has significant implications for subsequent derived parameters. Here, we revisit all previously reported LIFs using the updated luminous efficiency and expand the dataset to include all additional events recorded to date. Using meteoroid stream determination software [7], we identify the likely parent stream(s) of the impactors, from which we derive properties including impact velocity, impact angle, and density. For flashes observed in multiple wavelength bands, we determine the blackbody temperature of the emission, while for events persisting over multiple frames, we examine the temperature evolution throughout the flash duration. We additionally estimate the diameters of the resulting craters, providing constraints to support future crater searches with tools such as PyNAPLE. The revised luminous efficiency is larger than values previously adopted, meaning that a given impact generates more observable light and therefore corresponds to a smaller impactor than earlier estimates implied. This may account for the difficulty in detecting LIF-associated craters with PyNAPLE, as the craters produced by the faintest observable flashes are comparable to, or smaller than, the pixel scale of the Lunar Reconnaissance Orbiter Narrow Angle Camera (~0.5 m/px). We present the outcomes of these updated calculations along with revised statistical properties of the dataset, including the size–frequency distribution of the observed impacts. References1. Suggs R. M., Moser D. E., Cooke W. J., Suggs R. J., 2014, Icarus, 238, 232. Avdellidou C., et al., 2021, Planet. Space Sci., 200, 1052013. Sheward D., Delbo M., Avdellidou C., Cook A., Lognonné P., 2025, A&A,699, L34. Liakos A., Bonanos A. Z., Xilouris E. M., Koschny D., Bellas-Velidis I., Boumis P., Maroussis A., Moissl R., 2024, A&A, 687, A145. Sheward D., Avdellidou C., Cook A., Sefton-Nash E., Delbo M., Cantarella, B., Zanatta L., 2022, MNRAS, 514, 43206. Sheward D., Delbo M., Avdellidou C., Cook A., Lognonné P., 2025, A&A, 699, L37. Avdellidou C., Vaubaillon J., 2019, MNRAS, 484, 5212",
"id": "https://openalex.org/W7167047227",
"doi": "https://doi.org/10.5194/epsc2026-1021",
"title": "Statistical Analysis of Lunar Impact Flashes",
"display_name": "Statistical Analysis of Lunar Impact Flashes",
"publication_year": 2026,
"publication_date": "2026-07-02",
"ids": {
"openalex": "https://openalex.org/W7167047227",
"doi": "https://doi.org/10.5194/epsc2026-1021"
},
"language": null,
"primary_location": {
"id": "doi:10.5194/epsc2026-1021",
"doi": "https://doi.org/10.5194/epsc2026-1021",
"is_oa": true,
"landing_page_url": "https://doi.org/10.5194/epsc2026-1021",
"pdf_url": null,
"source": null,
"license": "cc-by",
"license_id": "https://openalex.org/licenses/cc-by",
"version": "acceptedVersion",
"is_accepted": true,
"is_published": false,
"raw_source_name": null,
"raw_type": "posted-content"
},
"volume": null,
"type": "conference-abstract",
"indexed_in": [
"crossref"
],
"open_access": {
"is_oa": true,
"oa_status": "gold",
"oa_url": "https://doi.org/10.5194/epsc2026-1021",
"any_repository_has_fulltext": null
},
"authorships": [
{
"author_position": "first",
"author": {
"id": "https://openalex.org/A5049119641",
"display_name": "Daniel Sheward",
"orcid": "https://orcid.org/0000-0003-1646-6932",
"observed_orcids": [
"https://orcid.org/0000-0003-1646-6932"
]
},
"institutions": [
{
"id": "https://openalex.org/I153648349",
"display_name": "University of Leicester",
"ror": "https://ror.org/04h699437",
"country_code": "GB",
"type": "education",
"lineage": [
"https://openalex.org/I153648349"
]
}
],
"countries": [
"GB"
],
"is_corresponding": false,
"raw_author_name": "Daniel Sheward",
"raw_affiliation_strings": [
"University of Leicester, Leicester, United Kingdom of Great Britain"
],
"raw_orcid": null,
"affiliations": [
{
"raw_affiliation_string": "University of Leicester, Leicester, United Kingdom of Great Britain",
"institution_ids": [
"https://openalex.org/I153648349"
]
}
]
},
{
"author_position": "middle",
"author": {
"id": "https://openalex.org/A5058537408",
"display_name": "Chrysa Avdellidou",
"orcid": "https://orcid.org/0000-0001-8228-8789",
"observed_orcids": [
"https://orcid.org/0000-0001-8228-8789"
]
},
"institutions": [
{
"id": "https://openalex.org/I153648349",
"display_name": "University of Leicester",
"ror": "https://ror.org/04h699437",
"country_code": "GB",
"type": "education",
"lineage": [
"https://openalex.org/I153648349"
]
}
],
"countries": [
"GB"
],
"is_corresponding": true,
"raw_author_name": "Chrysa Avdellidou",
"raw_affiliation_strings": [
"University of Leicester, Leicester, United Kingdom of Great Britain"
],
"raw_orcid": "https://orcid.org/0000-0001-8228-8789",
"affiliations": [
{
"raw_affiliation_string": "University of Leicester, Leicester, United Kingdom of Great Britain",
"institution_ids": [
"https://openalex.org/I153648349"
]
}
]
},
{
"author_position": "last",
"author": {
"id": "https://openalex.org/A5072686112",
"display_name": "Marco Delbò",
"orcid": "https://orcid.org/0000-0002-8963-2404",
"observed_orcids": [
"https://orcid.org/0000-0002-8963-2404"
]
},
"institutions": [
{
"id": "https://openalex.org/I1294671590",
"display_name": "Centre National de la Recherche Scientifique",
"ror": "https://ror.org/02feahw73",
"country_code": "FR",
"type": "government",
"lineage": [
"https://openalex.org/I1294671590"
]
},
{
"id": "https://openalex.org/I153648349",
"display_name": "University of Leicester",
"ror": "https://ror.org/04h699437",
"country_code": "GB",
"type": "education",
"lineage": [
"https://openalex.org/I153648349"
]
},
{
"id": "https://openalex.org/I4210113427",
"display_name": "Lagrange Laboratory",
"ror": "https://ror.org/02fdv8735",
"country_code": "FR",
"type": "facility",
"lineage": [
"https://openalex.org/I1294671590",
"https://openalex.org/I201841394",
"https://openalex.org/I4210113427",
"https://openalex.org/I4210126779",
"https://openalex.org/I4210148025"
]
},
{
"id": "https://openalex.org/I4210126779",
"display_name": "Observatoire de la Côte d’Azur",
"ror": "https://ror.org/039fj2469",
"country_code": "FR",
"type": "facility",
"lineage": [
"https://openalex.org/I1294671590",
"https://openalex.org/I201841394",
"https://openalex.org/I4210126779"
]
}
],
"countries": [
"FR",
"GB"
],
"is_corresponding": true,
"raw_author_name": "Marco Delbo",
"raw_affiliation_strings": [
"CNRS-Laboratoire Lagrange, Observatoire de la Cote d'Azur, Nice, France",
"University of Leicester, Leicester, United Kingdom of Great Britain"
],
"raw_orcid": "https://orcid.org/0000-0002-8963-2404",
"affiliations": [
{
"raw_affiliation_string": "CNRS-Laboratoire Lagrange, Observatoire de la Cote d'Azur, Nice, France",
"institution_ids": [
"https://openalex.org/I1294671590",
"https://openalex.org/I4210113427",
"https://openalex.org/I4210126779"
]
},
{
"raw_affiliation_string": "University of Leicester, Leicester, United Kingdom of Great Britain",
"institution_ids": [
"https://openalex.org/I153648349"
]
}
]
}
],
"institutions": [],
"countries_distinct_count": 2,
"institutions_distinct_count": 4,
"corresponding_author_ids": [
"https://openalex.org/A5058537408",
"https://openalex.org/A5072686112"
],
"corresponding_institution_ids": [
"https://openalex.org/I1294671590",
"https://openalex.org/I153648349",
"https://openalex.org/I4210113427",
"https://openalex.org/I4210126779"
],
"apc_list": null,
"apc_paid": null,
"fwci": null,
"has_fulltext": false,
"cited_by_count": 0,
"citation_normalized_percentile": null,
"cited_by_percentile_year": null,
"biblio": {
"volume": null,
"issue": null,
"first_page": null,
"last_page": null
},
"is_retracted": false,
"is_paratext": false,
"is_xpac": false,
"primary_topic": {
"id": "https://openalex.org/T10325",
"display_name": "Astro and Planetary Science",
"score": 0.9868000149726868,
"subfield": {
"id": "https://openalex.org/subfields/3103",
"display_name": "Astronomy and Astrophysics"
},
"field": {
"id": "https://openalex.org/fields/31",
"display_name": "Physics and Astronomy"
},
"domain": {
"id": "https://openalex.org/domains/3",
"display_name": "Physical Sciences"
}
},
"topics": [
{
"id": "https://openalex.org/T10325",
"display_name": "Astro and Planetary Science",
"score": 0.9868000149726868,
"subfield": {
"id": "https://openalex.org/subfields/3103",
"display_name": "Astronomy and Astrophysics"
},
"field": {
"id": "https://openalex.org/fields/31",
"display_name": "Physics and Astronomy"
},
"domain": {
"id": "https://openalex.org/domains/3",
"display_name": "Physical Sciences"
}
},
{
"id": "https://openalex.org/T10406",
"display_name": "Planetary Science and Exploration",
"score": 0.007499999832361937,
"subfield": {
"id": "https://openalex.org/subfields/3103",
"display_name": "Astronomy and Astrophysics"
},
"field": {
"id": "https://openalex.org/fields/31",
"display_name": "Physics and Astronomy"
},
"domain": {
"id": "https://openalex.org/domains/3",
"display_name": "Physical Sciences"
}
},
{
"id": "https://openalex.org/T11701",
"display_name": "Space Satellite Systems and Control",
"score": 0.0026000000070780516,
"subfield": {
"id": "https://openalex.org/subfields/2202",
"display_name": "Aerospace Engineering"
},
"field": {
"id": "https://openalex.org/fields/22",
"display_name": "Engineering"
},
"domain": {
"id": "https://openalex.org/domains/3",
"display_name": "Physical Sciences"
}
}
],
"keywords": [
{
"id": "https://openalex.org/keywords/lunar-impact-flashes",
"display_name": "lunar impact flashes",
"score": 0.9990000128746033
},
{
"id": "https://openalex.org/keywords/luminous-efficiency",
"display_name": "luminous efficiency",
"score": 0.9399999976158142
},
{
"id": "https://openalex.org/keywords/meteoroid-streams",
"display_name": "meteoroid streams",
"score": 0.7739999890327454
},
{
"id": "https://openalex.org/keywords/impactor-size-distribution",
"display_name": "impactor size distribution",
"score": 0.6060000061988831
},
{
"id": "https://openalex.org/keywords/impact-velocity",
"display_name": "impact velocity",
"score": 0.44999998807907104
},
{
"id": "https://openalex.org/keywords/impact-angle",
"display_name": "impact angle",
"score": 0.8970000147819519
},
{
"id": "https://openalex.org/keywords/blackbody-temperature",
"display_name": "blackbody temperature",
"score": 0.7250000238418579
},
{
"id": "https://openalex.org/keywords/crater-diameter",
"display_name": "crater diameter",
"score": 0.6129999756813049
},
{
"id": "https://openalex.org/keywords/lunar-impact-craters",
"display_name": "lunar craters",
"score": 0.4880000054836273
},
{
"id": "https://openalex.org/keywords/size-frequency-distribution",
"display_name": "size-frequency distribution",
"score": 0.5609999895095825
}
],
"concepts": [
{
"id": "https://openalex.org/C179537507",
"wikidata": "https://www.wikidata.org/wiki/Q55818",
"display_name": "Impact crater",
"level": 2,
"score": 0.6538000106811523
},
{
"id": "https://openalex.org/C32848918",
"wikidata": "https://www.wikidata.org/wiki/Q845789",
"display_name": "Observable",
"level": 2,
"score": 0.6389999985694885
},
{
"id": "https://openalex.org/C157909335",
"wikidata": "https://www.wikidata.org/wiki/Q900097",
"display_name": "Black-body radiation",
"level": 3,
"score": 0.5074999928474426
},
{
"id": "https://openalex.org/C62649853",
"wikidata": "https://www.wikidata.org/wiki/Q199687",
"display_name": "Remote sensing",
"level": 1,
"score": 0.503000020980835
},
{
"id": "https://openalex.org/C39432304",
"wikidata": "https://www.wikidata.org/wiki/Q188847",
"display_name": "Environmental science",
"level": 0,
"score": 0.4952999949455261
},
{
"id": "https://openalex.org/C204323151",
"wikidata": "https://www.wikidata.org/wiki/Q905424",
"display_name": "Range (aeronautics)",
"level": 2,
"score": 0.492900013923645
},
{
"id": "https://openalex.org/C10393806",
"wikidata": "https://www.wikidata.org/wiki/Q7012",
"display_name": "Meteoroid",
"level": 2,
"score": 0.4016999900341034
},
{
"id": "https://openalex.org/C121332964",
"wikidata": "https://www.wikidata.org/wiki/Q413",
"display_name": "Physics",
"level": 0,
"score": 0.36730000376701355
},
{
"id": "https://openalex.org/C68271606",
"wikidata": "https://www.wikidata.org/wiki/Q625648",
"display_name": "Photometry (optics)",
"level": 3,
"score": 0.35519999265670776
},
{
"id": "https://openalex.org/C51858381",
"wikidata": "https://www.wikidata.org/wiki/Q1504173",
"display_name": "Luminous efficacy",
"level": 3,
"score": 0.3248000144958496
},
{
"id": "https://openalex.org/C6260449",
"wikidata": "https://www.wikidata.org/wiki/Q41364",
"display_name": "Wavelength",
"level": 2,
"score": 0.3118000030517578
},
{
"id": "https://openalex.org/C153294291",
"wikidata": "https://www.wikidata.org/wiki/Q25261",
"display_name": "Meteorology",
"level": 1,
"score": 0.3091000020503998
},
{
"id": "https://openalex.org/C40636538",
"wikidata": "https://www.wikidata.org/wiki/Q81392",
"display_name": "Fractal",
"level": 2,
"score": 0.30329999327659607
},
{
"id": "https://openalex.org/C130066347",
"wikidata": "https://www.wikidata.org/wiki/Q680509",
"display_name": "Spectroradiometer",
"level": 3,
"score": 0.2879999876022339
},
{
"id": "https://openalex.org/C73329638",
"wikidata": "https://www.wikidata.org/wiki/Q527",
"display_name": "Sky",
"level": 2,
"score": 0.28679999709129333
},
{
"id": "https://openalex.org/C2986587452",
"wikidata": "https://www.wikidata.org/wiki/Q938438",
"display_name": "Statistical analysis",
"level": 2,
"score": 0.2840000092983246
},
{
"id": "https://openalex.org/C12287442",
"wikidata": "https://www.wikidata.org/wiki/Q105902",
"display_name": "Luminosity",
"level": 3,
"score": 0.2667999863624573
},
{
"id": "https://openalex.org/C95418871",
"wikidata": "https://www.wikidata.org/wiki/Q1666046",
"display_name": "Interferometric visibility",
"level": 4,
"score": 0.26109999418258667
},
{
"id": "https://openalex.org/C1276947",
"wikidata": "https://www.wikidata.org/wiki/Q333",
"display_name": "Astronomy",
"level": 1,
"score": 0.26089999079704285
},
{
"id": "https://openalex.org/C156034889",
"wikidata": "https://www.wikidata.org/wiki/Q408723",
"display_name": "Airglow",
"level": 2,
"score": 0.2606000006198883
},
{
"id": "https://openalex.org/C23576306",
"wikidata": "https://www.wikidata.org/wiki/Q17004698",
"display_name": "Astronomical interferometer",
"level": 3,
"score": 0.2597000002861023
},
{
"id": "https://openalex.org/C160633673",
"wikidata": "https://www.wikidata.org/wiki/Q355198",
"display_name": "Pixel",
"level": 2,
"score": 0.2556000053882599
}
],
"mesh": [],
"locations_count": 1,
"locations": [
{
"id": "doi:10.5194/epsc2026-1021",
"doi": "https://doi.org/10.5194/epsc2026-1021",
"is_oa": true,
"landing_page_url": "https://doi.org/10.5194/epsc2026-1021",
"pdf_url": null,
"source": null,
"license": "cc-by",
"license_id": "https://openalex.org/licenses/cc-by",
"version": "acceptedVersion",
"is_accepted": true,
"is_published": false,
"raw_source_name": null,
"raw_type": "posted-content"
}
],
"best_oa_location": {
"id": "doi:10.5194/epsc2026-1021",
"doi": "https://doi.org/10.5194/epsc2026-1021",
"is_oa": true,
"landing_page_url": "https://doi.org/10.5194/epsc2026-1021",
"pdf_url": null,
"source": null,
"license": "cc-by",
"license_id": "https://openalex.org/licenses/cc-by",
"version": "acceptedVersion",
"is_accepted": true,
"is_published": false,
"raw_source_name": null,
"raw_type": "posted-content"
},
"sustainable_development_goals": [],
"sustainable_development_goals_aurora": [],
"study_designs": [],
"awards": [],
"funders": [],
"has_content": {
"grobid_xml": false,
"pdf": false
},
"content_urls": null,
"referenced_works_count": 0,
"referenced_works": [],
"related_works": [],
"counts_by_year": [],
"updated_date": "2026-08-21T09:56:20.448147",
"created_date": "2026-07-03T00:00:00"
}