A massive impact on the Moon reveals a hidden danger for future lunar bases

A powerful collision struck the Moon in 2024, creating an enormous crater that went unnoticed until scientists examined images collected by NASA’s Lunar Reconnaissance Orbiter (LRO). The newly identified structure, officially named McGetchin, measures approximately 222 meters in diameter and reaches a depth of 43 meters, making it the largest newly formed impact crater discovered in the Solar System through contemporary observations. Two studies published in the peer-reviewed journal Science Advances on September 16, 2026, reveal that the event not only excavated an enormous amount of lunar material but also significantly altered the surrounding terrain, providing important evidence for understanding impact processes and evaluating the risks associated with future human exploration.

A collision that remained hidden for more than a year

The impact occurred between April 11 and May 22, 2024, when a fragment of an asteroid or comet, estimated to be comparable in size to a building three to six stories tall, collided with the Moon’s near side. Despite its considerable magnitude, the event was not detected in real time by telescopes on Earth or in space. The crater was eventually identified by researcher Robert Wagner on October 24, 2025, while comparing historical and recent images collected by LRO’s Wide Angle Camera. Subsequent high-resolution observations revealed its dimensions and the remarkable extent of the material ejected during the collision.

The newly discovered crater is approximately three times larger than the previous record-holder identified by the spacecraft, and statistical models suggest that an event of this magnitude occurs on the Moon roughly once every 132 years. Researchers also found that the impact disturbed the lunar surface at distances exceeding 100 kilometers from the crater, demonstrating that collisions can modify regions far beyond their immediate excavation zones. Unlike Earth, the Moon lacks a substantial atmosphere capable of destroying incoming meteoroids before they reach the surface, making impact cratering one of the principal processes responsible for continuously transforming its landscape.

A mysterious cold region surrounding the crater

A second investigation, using measurements from LRO’s Diviner Lunar Radiometer Experiment, revealed an unexpected thermal signature surrounding McGetchin. Scientists identified an approximately seven-kilometer-wide region that becomes eight to nine kelvins colder than neighboring terrain during the lunar night. The anomaly is consistent with a reduction in the density of the upper regolith caused by the impact, which disturbed and loosened the surface material, altering its thermal properties.

This observation provides important evidence for a process known as impact gardening, through which meteorite collisions repeatedly excavate, redistribute and overturn lunar soil. By examining McGetchin alongside other recently formed craters, researchers found that impacts producing craters larger than approximately 30 meters commonly generate detectable cold regions. Their results indicate that this mechanism may modify the upper layers of lunar regolith at rates comparable to those associated with direct crater excavation, suggesting that the Moon’s surface is more dynamically altered than its apparently ancient landscape might imply.

Why this discovery matters for future Moon missions

The implications extend directly to the engineering challenges of establishing a sustained human presence on the lunar surface. A large impact can scatter debris across extensive distances, potentially threatening habitats, scientific instruments, vehicles and other infrastructure located far from the collision site. Furthermore, changes in regolith density and mechanical properties could affect the performance of robotic rovers and other equipment operating on disturbed terrain.

The findings also challenge the popular assumption that astronaut footprints left during the Apollo missions will remain preserved indefinitely. Based on accumulated observations of newly formed craters, researchers estimate that the uppermost two centimeters of lunar soil may be overturned by impact ejecta on timescales of approximately 80,000 years, although the survival of individual footprints depends on local conditions and subsequent impacts. By documenting the physical consequences of an exceptionally large collision, the new studies offer valuable constraints for improving impact-frequency models, understanding lunar surface evolution and designing more resilient infrastructure for future exploration.

The discovery of McGetchin demonstrates that the Moon is not a geologically unchanging world. Even without widespread active volcanism or terrestrial-style plate tectonics, cosmic impacts continue to reshape its surface, sometimes with consequences extending dozens of kilometers beyond the original collision. Understanding these processes will be essential as humanity prepares to move from brief lunar visits toward long-term operations on another celestial body.

© 2026 Homer Dávila Gutiérrez, FRAS — SKYCR.ORG. All rights reserved. Mark S. Robinson et al., A new 222-m diameter lunar crater. Science Advances, 12(38), eaeh7812 (2026). DOI: 10.1126/sciadv.aeh7812. Tyler M. Powell et al., New lunar crater reveals extensive distal regolith modification. Science Advances, 12(38), eaeh9568 (2026). DOI: 10.1126/sciadv.aeh9568 .