Scientists have identified the largest newly formed impact crater ever found in the solar system, after a NASA researcher noticed an unusual bright spot while conducting a routine data check on lunar imagery. The discovery, formally named McGetchin crater, was reported September 15, 2026, in a pair of papers published in the journal Science Advances.

How the Discovery Happened

The finding began almost by accident. Robert Wagner, an image-processing specialist from Intuitive Machines who works with data from the Lunar Reconnaissance Orbiter Camera (LROC) system, was scanning a giant map of the Moon on his computer screen when an unusually large bright spot circled by a dark halo caught his eye — a pattern implying that surface material in that area had been dramatically disturbed. "I just stopped, dropped everything, and started looking into what that spot was," Wagner said. By comparing before-and-after images of the Moon's surface, he realized he had found something unprecedented.

How the Comparison Worked

Wagner built a global map of the Moon by stitching together hundreds of images from the Wide-Angle Camera aboard NASA's Lunar Reconnaissance Orbiter (LRO), using two sets of images taken several years apart. He then applied software designed to highlight changes between the two datasets: anything that stayed the same turned gray, while anything different appeared as bright or dark patches — a technique that made McGetchin crater's ejecta pattern immediately stand out.

When and How the Crater Formed

The crater formed on the Moon's eastern edge sometime between April 11 and May 22, 2024, after a comet or asteroid roughly the size of a three- to six-story building struck the lunar surface. Scientists estimate an impact of this magnitude occurs on the Moon only about once a century, or even less frequently — making this a genuinely rare event to capture in the relatively short window of modern lunar surveillance.

The Crater's Actual Size

McGetchin crater itself measures approximately 728 feet wide. What first caught scientists' attention wasn't the crater itself, but the bright white material flung outward (ejecta) from the impact, visible in imagery covering an area roughly 38 miles wide.

The Name's Origin

The crater is officially named after Tom McGetchin, a pioneering lunar scientist, honoring his contributions to the study of the Moon's geology.

A Distinctive Thermal Signature

Using NASA's Diviner thermal instrument aboard LRO, scientists mapped surface temperatures around the crater between November 15, 2025, and February 18, 2026, comparing them against pre-impact temperature data from the Diviner Global High-Resolution Mosaics (GHRM). The analysis revealed a striking feature: a 4-mile-wide "cold spot" surrounding the crater that runs roughly 16 degrees Fahrenheit cooler at night than the surrounding terrain. Scientists explain this cooling occurs because the impact "fluffs up" the regolith — the loose surface material — around the crater, making it less dense and therefore less able to retain heat overnight compared to undisturbed lunar soil.

Why This Matters Beyond a Single Crater

The discovery underscores the ongoing scientific value of NASA's Lunar Reconnaissance Orbiter, which has now been circling the Moon for more than 17 years, using its seven instruments to map lunar topography, surface composition, temperature, and radiation environment. Over the course of its mission, the LRO team has identified at least 1,000 new impact craters and flagged more than 100,000 additional surface changes caused by objects striking the Moon or by debris flung out from those impacts.

Relevance to Future Lunar Missions

This discovery carries practical significance beyond pure science: as NASA advances plans for a sustained human presence and expanded scientific and commercial activity on the Moon, understanding the rate, scale, and distribution of impact events becomes increasingly important for assessing risk to future lunar infrastructure, habitats, and astronauts working on the surface.

Part of a Longer Pattern of Impact Detection

LRO has a well-established track record of catching lunar impacts as they happen. In 2013, the orbiter's camera team discovered an 18-meter-wide crater caused by a bright flash observed in Mare Imbrium. More recently, LRO confirmed the impact site of a spent rocket body that struck the Moon in March 2022, and separately identified a small crater in 2023 believed to be the impact site of Russia's failed Luna-25 lunar lander. McGetchin crater stands apart from these earlier finds by a wide margin, given its status as the largest newly formed crater yet documented anywhere in the solar system.

What's Next

With the discovery now formally published, scientists are expected to continue studying McGetchin crater's characteristics — including its thermal signature and ejecta pattern — for further insight into impact dynamics that could inform planning for future lunar exploration. For the full findings, see the official NASA Science announcement.