LRO Spots Once-in-Century Moon Crater McGetchin

NASA's Lunar Reconnaissance Orbiter has found the largest newly formed impact crater ever identified in the solar system, a 728-foot scar blasted into the Moon in 2024.

Scientists announced the discovery of McGetchin crater, a 728-foot-wide (222-meter), 141-foot-deep (43-meter) impact feature on the Moon's eastern edge that formed sometime between April 11 and May 22, 2024, when a comet or asteroid the size of a three- to six-story building struck the surface. NASA and reporting in two studies published Sept. 16, 2026 in Science Advances call it the largest newly formed crater ever found in the solar system, and estimate such impacts occur only about once every 132 years — a statistically rare, effectively once-in-a-lifetime observation.

The collision escaped real-time detection by telescopes on Earth and in space, and LRO's wide-angle images sat unidentified in a crush of data until researcher Robert Wagner of Intuitive Machines noticed an unusually large bright spot ringed by a dark halo during a routine data-quality check on Oct. 24, 2025. According to Popular Science, specialized software designed to highlight changes in shadows and lighting produces hundreds of false leads, so Wagner examined the images pixel by pixel before confirming the debris pattern. "It was by far the most obvious impact debris pattern I've ever seen in one of these images," Wagner said, per Gizmodo. The crater is three times bigger than the previous LRO record-holder found a decade ago, The Weather Channel/AP reports.

The white mark Wagner spotted was not the crater itself but material flung outward by the blast. According to Space Daily, the ejecta still gleams because freshly excavated rock and dust has not yet been darkened by space weathering, and debris was thrown at higher angles than standard models predict. Follow-up observations by LRO's Diviner thermal instrument found a roughly 4-mile-wide (7-kilometer) cold spot around the crater, measuring about 14 to 16 degrees Fahrenheit (8 to 9 kelvins) cooler at night than its surroundings — a sign the impact fluffed up the regolith, making it less dense and less able to retain heat.

Most lunar craters are ancient and altered by space weathering and later bombardment, so McGetchin's pristine condition — bracketed by before-and-after images to a seven-week window in 2024 — gives scientists something lunar geology rarely supplies: a large impact feature with a known start date measured in weeks. According to space.com, the crater formed along a boundary between dark mare basalt and brighter highland crust, letting researchers study how one impact affects two distinct terrains, and a rover or crewed mission could examine features orbiters cannot fully resolve.

The impact churned the lunar surface more than 66 miles from the point of strike, with dust and rocky soil hurled at higher angles than expected, according to LRO camera chief scientist Mark Robinson, per The Weather Channel/AP. Robinson told the outlet the next step is calculating the risk of ejected material striking NASA's planned moon base, so engineers can harden structures. LRO data also shows the Moon's top inch of soil is overturned every 80,000 years, faster than previously thought — meaning even the Apollo astronauts' footprints will eventually fade, contrary to popular belief.

The crater was named for pioneering lunar scientist Thomas R. McGetchin, a former director of Houston's Lunar and Planetary Institute who helped develop models of how ejecta is distributed around impact craters — a naming that Space Daily notes is unusually apt as the crater tests assumptions about ejection angles and layered deposition. Researchers are still determining the impactor's exact size and force, and Popular Science reports that LRO's Narrow-Angle Camera, with roughly three-foot-per-pixel resolution, will support that work in a forthcoming study.