NASA Orbiter Finds a 728-Foot, Once-in-a-Century Moon Crater
NASA's Lunar Reconnaissance Orbiter has located a 728-foot-wide impact crater on the Moon, described by the agency as the largest modern-day crater in the solar system. The feature, named McGetchin crater, was reported by NASA scientists on Sept. 15, 2026, in an announcement titled "NASA's Moon Orbiter Spots New, 'Once-in-Century' Moon Crater" NASA.
The crater measures 728 feet wide and 141 feet deep, with steep-sided walls. NASA describes it as spanning the length of two football fields NASA. Separate reporting noted it is bigger than the Roman Colosseum. That scale sets it well apart from the small, meter-scale pits that orbital imaging usually records.
The impact that formed it occurred between April 11 and May 22, 2024. The impactor was a comet or asteroid about the size of a three- to six-story building Engadget. Scientists estimate an impact of this size happens only once every 132 years.
The detection was human. NASA scientist Robert Wagner noticed the change in October 2025 while reviewing images from the orbiter's wide-angle camera, which scans broad areas. The spacecraft flew over the site again in December 2025, when its narrow-angle camera, built for fine detail, photographed the site at higher resolution.
That two-step sequence is standard for mapping from orbit. Wide-angle coverage builds a repeat baseline to spot change. Narrow-angle follow-up shows shape and structure. In this case the second pass confirmed a fresh excavation, not a trick of light or a processing error.
Thermal data added a third signature. A 4-mile-wide area around McGetchin crater is about 16 degrees Fahrenheit cooler at night. The crater was officially named after scientist Tom McGetchin.
The broader context here is impact rate calibration, or how scientists estimate how often objects of a given size strike. For readers used to rare events, a single well-measured case can carry extra weight. A crater with a known time window, known dimensions, and known impactor size gives modelers a fixed anchor for the present-day rate. One event does not rewrite lunar history by itself, but it narrows uncertainty around how often mid-size impactors hit an airless body near Earth.
Looking at what this means for operations in cislunar space, the region around Earth and the Moon, the value is in steady monitoring rather than any single find. LRO has been in lunar orbit for years, and its archive allows before-and-after comparison across much of the surface. Change detection at that scale is a data-management problem as much as an optics problem. Terabytes of repeat images must stay aligned and consistently calibrated so a new 200-meter-class feature stands out to an algorithm or, as here, to an analyst doing systematic review.
In my view, worth flagging is how ordinary the workflow sounds, and why that is encouraging. No new sensor was required. No dedicated impact-watch fleet was deployed. Long-lived infrastructure, stable calibration, and careful human inspection produced a once-in-a-century observation more than a year after the event. That interval matters. It suggests other recent changes are already in the archive, waiting for reprocessing or re-examination to surface them.
Over the long arc, in my view, the optimistic read is straightforward. Better knowledge of small-body numbers and impact energy improves spacecraft shielding, surface site choice, and risk models for sustained lunar activity. It also refines understanding of how quickly the surface is churned on human timescales, rather than geologic ones. The Moon is often treated as static. McGetchin crater is evidence it is not.
