A crater 728 feet (222 meters) wide that did not exist in early 2024 now marks the Moon's eastern edge, and scientists say it is the largest newly formed crater ever found in the solar system. NASA's Lunar Reconnaissance Orbiter (LRO) captured the before-and-after images, and two papers published Sept. 16 in the journal Science Advances describe the crater, named McGetchin, and the unexpectedly large area of lunar soil it disturbed, NASA said.

The impact happened sometime between April 11 and May 22, 2024, when a comet or asteroid roughly the size of a three- to six-story building struck the Moon's eastern edge. The resulting crater is 141 feet (43 meters) deep, enough to hold three school buses stacked on end. Before this discovery, the largest recently formed crater found on the Moon measured an estimated 230 feet (70 meters) across, CNN reported.

For people on Earth, the finding has no safety implications. It matters because it offers a rare look at a fresh, large impact at a time when NASA and other nations plan to land more robots and astronauts on the lunar surface, where there is no atmosphere to slow or burn up incoming rocks.

Spotted in a Before-and-After Search

The crater was found by Robert Wagner, an image-processing specialist with Intuitive Machines who works with data from the Lunar Reconnaissance Orbiter Camera. On Oct. 24, 2025, during a periodic search for surface changes wider than about 150 feet, he stacked hundreds of older and newer wide-angle images using software that shows unchanged terrain in gray and changes as bright or dark patches.

One spot stood out: a large bright area circled by a dark halo, the signature of freshly thrown lunar soil. "I just stopped, dropped everything, and started looking into what that spot was," Wagner said in NASA's announcement. The debris pattern spanned hundreds of pixels, far larger than the tiny fuzzy halos he usually checks.

The team then used LRO's Narrow-Angle Camera, which resolves details of about 3 feet per pixel, to measure the crater on later passes. A close-up image taken on Dec. 5, 2025, shows the sharp rim and bright ejecta. The object's size and impact force will be detailed in a future paper, NASA said.

A Four-Mile Cold Spot Around the Crater

A second team examined the site with LRO's Diviner instrument, which measures surface temperature. In a companion Science Advances paper, they reported a zone about 4 miles wide around McGetchin that is roughly 16 degrees Fahrenheit colder at night than surrounding terrain.

The researchers attribute the difference to changes in the regolith, the loose layer of dust and broken rock on the lunar surface. The impact fluffed up the soil around the crater, leaving it less dense and less able to hold heat after sunset. The size of that cold zone is striking, scientists said, because it shows that an impact can modify the surface far beyond the crater itself.

That has practical consequences. NASA noted that such physical changes to the regolith could affect how rover wheels interact with the surface, which matters for planning where to land or drive equipment.

A Once-in-a-Lifetime Observation, With Limits

The Moon is hit constantly. Over more than 17 years in orbit, LRO has helped scientists identify at least 1,000 new impact craters and flag about 100,000 other surface changes caused by impacts or flying debris. Most are small: rocks about 43 inches wide create an estimated 140 craters about 30 feet across each year.

Impacts the size of McGetchin are far rarer. "Crater production models indicate that an impact of this magnitude is expected to occur only once every 132 years on the Moon," the authors wrote in the discovery paper, calling the event an effectively once-in-a-lifetime observation. NASA describes the frequency as about once a century or even longer.

The evidence here is strong but has clear boundaries. The crater's size and formation window come from direct before-and-after imaging, and both studies are peer-reviewed. The impact date is known only to within a roughly six-week window, and the impactor's size and energy have not yet been published by the team. The recurrence estimate comes from crater production models rather than direct observation, and the largest-ever label applies to craters seen forming in the era of spacecraft monitoring, not to the Moon's ancient, far larger craters.

The crater is officially named McGetchin after Tom McGetchin, a pioneering lunar scientist of the Apollo era.

A Natural Laboratory for Future Missions

Scientists say fresh craters are valuable because they show what a surface looks like before space weathering darkens and blurs it. Watching McGetchin's bright ejecta and cold halo change over years could help researchers better understand how young craters evolve.

The discovery also highlights the value of long-running monitoring missions. LRO, launched in 2009, has photographed the Moon in enough detail and often enough to catch changes that would otherwise go unnoticed. NASA said the finding shows the value of that record as the agency works toward a sustained human presence and expanded scientific and commercial activity on the Moon.

Readers can view the before-and-after images, the thermal map, and the close-up of McGetchin through NASA's announcement, and Scientific American has also summarized the findings. There is no risk to Earth from impacts of this kind on the Moon.

The next step is the forthcoming paper on the impactor itself, along with continued LRO observations of how the site changes. McGetchin is a small scar on an ancient surface, but it is the clearest look scientists have had at a large impact reshaping another world in near real time.

What Readers Want to Know

How big is the new McGetchin crater?

It is about 728 feet (222 meters) wide and 141 feet (43 meters) deep, roughly the length of two football fields.

When did the crater form?

Sometime between April 11 and May 22, 2024, based on images taken before and after the impact.

How was the crater discovered?

Image-processing specialist Robert Wagner spotted it on Oct. 24, 2025, while comparing older and newer wide-angle images from NASA's Lunar Reconnaissance Orbiter.

What is the cold spot around the crater?

An area about 4 miles wide around McGetchin is roughly 16 degrees Fahrenheit colder at night because the impact loosened the lunar soil, which then holds less heat.

How often do impacts this large hit the Moon?

Crater production models suggest an impact of this size happens about once every 132 years, and NASA describes it as about once a century or longer.

Could something similar hit Earth?

Earth's atmosphere slows and breaks up many incoming rocks, unlike the airless Moon. This lunar impact posed no risk to Earth.