A routine review of data from the Lunar Reconnaissance Orbiter led to a striking find on the Moon, as scientists identified a fresh impact crater now named McGetchin.
Robert Wagner, an image-processing specialist with Intuitive Machines who works with the Lunar Reconnaissance Orbiter Camera system, noticed an unusually bright patch ringed by a darker halo while scanning a global map. Comparing recent and archival images confirmed a new impact. Researchers reported on September 16 in Science Advances that it is the largest newly formed crater identified in the solar system to date. The discovery underscores the value of NASA’s long-term lunar monitoring as the agency moves toward sustained human activity and expanded science and commercial operations on the Moon.
Lunar Reconnaissance Orbiter reveals rare giant impact
The crater, officially named McGetchin for lunar scientist Tom McGetchin, formed near the Moon’s eastern limb between April 11 and May 22, 2024, when an asteroid or comet roughly the height of a three- to six-story building struck the surface. The impact excavated a cavity 728 feet wide and about 141 feet deep. Events of this scale may occur on the Moon roughly once per century, or even less often, according to researchers.
The Moon is continually bombarded
For more than 17 years, the Lunar Reconnaissance Orbiter has circled the Moon with seven instruments characterizing topography, composition, temperatures, and radiation. In that period, scientists have cataloged at least 1,000 new impact craters and roughly 100,000 additional surface changes from direct strikes or ejecta. With no atmosphere to slow or burn up incoming objects, the lunar surface takes impacts from asteroids, meteoroids, and other debris directly.
Most impacts are far smaller than McGetchin. The smallest new craters reliably detected in LRO images measure about 30 feet across, produced by impactors around 43 inches wide. Researchers estimate about 140 such craters form across the Moon each year. Even more numerous micrometeoroid hits produce holes too small to resolve from orbit.
A four-mile nighttime cold spot
After McGetchin was identified, scientists used LRO’s Diviner thermal instrument to assess the surrounding terrain. They found a region roughly four miles across that is about 16 degrees Fahrenheit colder at night than adjacent ground. A companion paper in Science Advances on September 16 attributes the temperature drop to changes in the regolith. The impact churned and loosened surface material, reducing its density and its ability to retain heat after sunset.
The scale of this cold anomaly indicates that large impacts significantly modify the lunar environment beyond the crater rim, with potential implications for exploration. Variations in regolith texture and packing, for example, could affect rover mobility.
How the team pinpointed the crater
The LROC system acquires imagery from about 60 miles above the surface as LRO flies a polar orbit. Two Narrow-Angle Cameras collect high-resolution black-and-white views and a Wide-Angle Camera records moderate-resolution multispectral images. Over thousands of passes, researchers have assembled global maps used to spot newly formed craters, landslides, landers, faults, and possible lava tube skylights.
While LROC teams routinely inspect Narrow-Angle images for changes under 30 feet across, every few years they conduct broader surveys by comparing global maps to flag larger features, typically changes wider than 150 feet. Wagner was performing one of these surveys on October 24, 2025, when McGetchin stood out. Using the Wide-Angle Camera, he combined hundreds of before-and-after frames with software tuned to highlight differences. Stable terrain appears gray. Altered areas show bright or dark patches.
An impact signature impossible to miss
Although the method is powerful, identifying true new craters requires extensive manual checks because lighting variations can trigger false positives. Analysts usually look for small fuzzy halos around point-like brightness features indicative of fresh ejecta. McGetchin was different. Its debris pattern spanned hundreds of pixels, immediately distinguishing it from surrounding terrain.
Follow-up imaging with the Narrow-Angle Camera, at roughly 3 feet per pixel, enabled precise measurements of the crater’s size, morphology, and the extent of surface disturbance. Those data also informed estimates of the impactor’s size and energy. More detailed analyses are expected in a future paper.
According to the teams working with the Lunar Reconnaissance Orbiter, the McGetchin discovery highlights both the dynamic nature of the lunar surface and the value of sustained orbital observations for science and future missions. Related work is also refining how space weather shapes conditions throughout near-Earth space.