NASA’s Lunar Reconnaissance Orbiter has discovered McGetchin, the largest newly formed crater ever found in the solar system. Spanning 728 feet wide and 141 feet deep on the Moon’s eastern edge, the colossal crater was carved between April 11 and May 22, 2024, by an incoming celestial impact.
A routine data check on a computer screen revealed what researchers now recognize as a landmark planetary event. Robert Wagner, an image-processing specialist from Intuitive Machines working with data from the Lunar Reconnaissance Orbiter Camera system, spotted a large bright spot circled by a dark halo while reviewing giant lunar maps. Realizing the pattern indicated massive surface disruption, he compared before-and-after images of the region and confirmed the discovery.
The impact crater emerged on the Moon’s eastern edge sometime between April 11 and May 22, 2024. Researchers determined it was created when an asteroid or comet roughly the size of a three- to six-story building slammed into the lunar surface. The resulting excavation left a cavity 728 feet wide—spanning the length of two football fields—and 141 feet deep, offering ample room to swallow three vertically stacked school buses.
The Geology of McGetchin and a Once-in-a-Century Impact
Scientists formally named the site McGetchin in honor of the pioneering lunar scientist Tom McGetchin. An impact of this sheer scale is exceptionally rare. Researchers calculate that objects capable of carving craters of this magnitude strike the lunar surface only once per century or even less frequently, making its capture during the operational window of the orbiter an extraordinary stroke of fortune.
Unlike Earth, whose dense atmosphere burns up most incoming space debris through frictional heat and deceleration, the Moon sits in a near-vacuum. This leaves its terrain entirely vulnerable to impactors, which strike at velocities reaching tens of kilometers per second. While the mission has logged at least 1,000 new impact craters and flagged 100,000 surface changes over nearly two decades of operation, none rival the proportions of McGetchin. The fresh exposure of pristine subsurface material untouched by space weathering or radiation for hundreds of millions of years provides researchers with valuable primary data regarding the internal geological structure of our celestial neighbor.
Cold Spots, Ejected Debris, and Far-Reaching Surface Changes
The consequences of the collision extend far beyond the perimeter of the crater itself. Follow-up observations conducted with the orbiter’s thermal instrument, Diviner, revealed a sprawling four-mile-wide area surrounding the crater that registers roughly 16 degrees Fahrenheit cooler at night than the surrounding terrain. Researchers attribute this temperature drop to the impact thoroughly churning and fluffing up the lunar regolith, lowering its overall density and diminishing its capacity to retain heat.
Furthermore, analysis of ejected material showed that debris flung outward disturbed the surface more than 75 miles from the crater center. These widespread alterations highlight how energetic impacts actively churn regolith across the lunar landscape.
Implications for Future Lunar Habitats and Exploration
As space agencies and private enterprises advance plans for sustained human presence and infrastructure development on the Moon, understanding the physical properties of modified terrain becomes an urgent priority. The altered density of the regolith and the expansive reach of impact debris introduce physical variables that will influence how rover wheels traverse the soil and how engineers construct permanent installations.
Documenting the mechanics of a massive celestial impact provides critical baseline metrics for assessing projectile hazards to future bases and evaluating safety parameters for astronauts participating in international exploration initiatives. Quantifying the fallout zone helps planners calculate the distribution risks of high-velocity ejecta, ensuring that surface assets can be properly hardened against the ongoing bombardment shaping the lunar surface.