NASA's Lunar Orbiter Finds the Largest Newly Formed Crater Ever Recorded in the Solar System

Robert Wagner, an image-processing specialist working with NASA's Lunar Reconnaissance Orbiter program, discovered the largest newly formed crater ever found in the solar system on October 24, 2025, while reviewing routine data from the Moon's eastern edge, NASA reported.

The crater, now officially named McGetchin, formed sometime between April 11 and May 22, 2024, according to NASA's science reporting page at science.nasa.gov. An asteroid or comet roughly the size of a three- to six-story building struck the surface and left a hole 728 feet wide and 141 feet deep. NASA puts that in plain terms: the width spans two football fields, and the depth could swallow three school buses stacked end to end.

Scientists estimate an impact of this scale happens on the Moon about once every 132 years, according to the research published September 16, 2026, in the journal Science Advances.

How Wagner Found It

Wagner was not hunting for a record. He was doing a data-quality check, stacking hundreds of before-and-after frames from the Lunar Reconnaissance Orbiter Camera's Wide-Angle Camera to look for surface changes. The software he uses flags shifts in color or brightness, but it generates a lot of false alarms. His usual method is to scan for small, fuzzy halos around pixel-wide bright points, the kind of smear that a fresh crater leaves when ejected material sprays outward.

McGetchin did not look like a small fuzzy halo.

"It was by far the most obvious impact debris pattern I've ever seen in one of these images," Wagner said, as quoted by NASA on science.nasa.gov. The debris pattern stretched across hundreds of pixels. Wagner said he stopped what he was doing immediately. "I just stopped, dropped everything, and started looking into what that spot was."

He confirmed the find by comparing older imagery of the region with newer imagery, according to NASASpaceFlight.com, which reported on the discovery. Once the crater was confirmed, the team turned the orbiter's Narrow-Angle Camera on the site. That camera, which NASASpaceFlight.com says images the surface from an altitude of 96.5 kilometers, captures detail fine enough to measure the crater's dimensions, examine its shape, and estimate the size of the object that caused it.

What the Crater Tells Scientists

The crater is named McGetchin in honor of Tom McGetchin, a pioneering lunar scientist, according to NASA. The naming is confirmed in the Science Advances papers published September 16.

The impact did more than punch a hole. Scientists used LRO's Diviner Lunar Radiometer Experiment, a thermal instrument aboard the spacecraft, to examine the area around the crater after the discovery. They found a zone roughly 4 miles wide surrounding McGetchin that runs about 16 degrees Fahrenheit cooler at night than the terrain around it, according to NASA's science.nasa.gov report. A second paper, also published September 16 in Science Advances, covers this finding.

The explanation, according to that research: the impact churned and loosened the regolith, the layer of broken rock and dust that covers the lunar surface, for a wide area around the crater. Looser, less dense material holds heat less effectively, so it cools faster once the sun goes down.

The size of that cold zone surprised researchers. NASA noted on science.nasa.gov that the finding shows impacts can alter the lunar surface well beyond the crater rim itself. The agency pointed to one practical consequence: differences in regolith density and texture could affect how rover wheels grip and move across the surface, which matters for planning future missions.

Seventeen Years of Watching the Moon Change

LRO has been orbiting the Moon since 2009, according to NASA. Over more than 17 years, the spacecraft's team has identified at least 1,000 new impact craters and flagged more than 100,000 surface changes caused by objects striking the Moon or by debris thrown outward after impacts, NASA reported on science.nasa.gov.

Most of those craters are far smaller than McGetchin. The smallest craters LRO can detect in its images are about 30 feet wide, made by rocks roughly 43 inches across, about the size of a monster-truck tire, according to NASA. Impacts at that scale produce an estimated 140 new craters across the Moon each year, NASA said. Microscopic projectiles hit far more often, but the holes they leave are too small to see from orbit.

The Moon has no atmosphere to slow incoming objects or burn them up, so space rocks reach the surface at full speed. That is why the crater count keeps climbing.

What Comes Next

Two papers on McGetchin are now published in Science Advances, one covering the discovery and one covering the Diviner thermal findings, according to NASASpaceFlight.com. Additional research on the impact is expected, NASASpaceFlight.com reported, though no publication date for that work is confirmed in the material available.

What is not yet known: the precise date the impact occurred. Scientists have narrowed the window to between April 11 and May 22, 2024, but the exact moment is not in the record.

NASA has said the McGetchin discovery demonstrates the value of continuous orbital monitoring as the agency works toward sustained human presence on the Moon. The cold spot finding in particular gives mission planners a new data point: a single large impact can reshape the surface across a zone many times wider than the crater itself, and that reshaped ground is something any future crew or rover will have to account for.

LRO keeps circling. Wagner keeps checking the data.

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