Lunar ejecta as the missing piece to resolve the lunar cratering asymmetry

Fuente: arXiv
Gespeichert in:
Bibliographische Detailangaben
Hauptverfasser: Li, Hailiang, Zhang, Xiaoping, Zhou, Li-Yong
Format: Preprint
Veröffentlicht: 2026
Schlagworte:
Online-Zugang:
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
_version_ 1866914551736303616
author Li, Hailiang
Zhang, Xiaoping
Zhou, Li-Yong
author_facet Li, Hailiang
Zhang, Xiaoping
Zhou, Li-Yong
contents The leading-trailing asymmetry in lunar crater distribution provides a critical record of inner solar system dynamics, yet the long-standing discrepancy between the observed higher asymmetry and lower theoretical predictions indicates a gap in our understanding of the impactor population. This paper hypothesizes that lunar impact ejecta, which can enter Earth-like orbits and return, constitute a previously unaccounted-for component. Through numerical simulations, we find that ~25% of escaped ejecta will re-impact the Earth-Moon system within 3 Myr, with about 1.2% striking the Moon. Crucially, these lunar impacts exhibit an extreme leading-trailing asymmetry with a ratio of 5.9. Our results indicate that lunar ejecta, if comprising ~15% of total impactors, can fully explain the observed asymmetry, leading to their recognition as active agents shaping the lunar impact record. This work provides new constraints for understanding the impact environment of the Earth-Moon system, with direct relevance to the interpretation of lunar geology, the transport of lunar material to Earth, and ongoing space exploration missions.
format Preprint
id arxiv_https___arxiv_org_abs_2605_09884
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Lunar ejecta as the missing piece to resolve the lunar cratering asymmetry
Li, Hailiang
Zhang, Xiaoping
Zhou, Li-Yong
Earth and Planetary Astrophysics
The leading-trailing asymmetry in lunar crater distribution provides a critical record of inner solar system dynamics, yet the long-standing discrepancy between the observed higher asymmetry and lower theoretical predictions indicates a gap in our understanding of the impactor population. This paper hypothesizes that lunar impact ejecta, which can enter Earth-like orbits and return, constitute a previously unaccounted-for component. Through numerical simulations, we find that ~25% of escaped ejecta will re-impact the Earth-Moon system within 3 Myr, with about 1.2% striking the Moon. Crucially, these lunar impacts exhibit an extreme leading-trailing asymmetry with a ratio of 5.9. Our results indicate that lunar ejecta, if comprising ~15% of total impactors, can fully explain the observed asymmetry, leading to their recognition as active agents shaping the lunar impact record. This work provides new constraints for understanding the impact environment of the Earth-Moon system, with direct relevance to the interpretation of lunar geology, the transport of lunar material to Earth, and ongoing space exploration missions.
title Lunar ejecta as the missing piece to resolve the lunar cratering asymmetry
topic Earth and Planetary Astrophysics
url https://arxiv.org/abs/2605.09884