Sometime in spring 2024, a comet or asteroid possibly the size of a three- to six-story building slammed into the Moon's eastern edge. It carved what scientists describe as the largest newly formed crater ever found in the solar system, and no one noticed it at the time. The impact happened between April 11 and May 22, 2024, but the crater was not spotted until Oct. 24, 2025, during a routine comparison of before-and-after images from NASA's Lunar Reconnaissance Orbiter, according to NASA's announcement of the once-in-a-century crater.

The crater, now officially named McGetchin, is 728 feet (222 meters) wide, about the length of two football fields. At 141 feet (43 meters) deep, it could hold three school buses stacked on end. Around it, the orbiter's thermal instrument found a zone about 4 miles wide that runs roughly 16 degrees Fahrenheit (about 9 degrees Celsius) colder at night than the surrounding ground.

The find matters beyond the record. NASA is working toward a sustained human presence on the Moon, and McGetchin gives scientists a rare fresh look at how often large rocks hit the lunar surface and how far each impact disturbs the ground around it.

A Routine Data Check Turns Up a Record

The discovery began as a data-quality check. Robert Wagner, an image-processing specialist with Intuitive Machines who works with data from the orbiter's camera system, was scanning a global Moon map built by stacking hundreds of Wide-Angle Camera images taken years apart. Software turned unchanged areas gray and flagged anything new as bright or dark patches.

Most flags are false alarms caused by shifts in lighting and shadow, so Wagner usually looks for small fuzzy halos around pixel-wide bright points. McGetchin spanned hundreds of pixels. "I just stopped, dropped everything, and started looking into what that spot was," Wagner said. "It was by far the most obvious impact debris pattern I've ever seen in one of these images."

After the discovery, the sharper Narrow-Angle Camera, which resolves about 3 feet per pixel, photographed the site on Dec. 5, 2025, and revealed the crater's size and shape. The findings were reported in the first of two papers in Science Advances, published Sept. 16.

The impact also went undetected in real time, The Associated Press reported. McGetchin is about three times wider than the previous record holder among newly formed lunar craters, which measured an estimated 230 feet (70 meters) and was found by the orbiter about a decade ago, according to CNN. The crater is named for the late Thomas McGetchin, an Apollo-era lunar scientist and former director of the Lunar and Planetary Institute in Houston.

A Four-Mile Cold Zone and Loosened Soil

The crater itself is only part of the story. Scientists on the orbiter's Diviner thermal team observed the site between Nov. 15, 2025, and Feb. 18, 2026, and compared the readings with temperature maps made before the impact. The result was a cold spot about 4 miles across.

A second Science Advances paper on the cold zone explains the likely cause. The impact fluffed up the regolith, the loose soil and dust covering the Moon, making it less dense and less able to hold heat after sunset. NASA said the size of the cold spot is striking because it shows that an impact can modify the surface far beyond the crater itself.

The camera team found a similar pattern. Mark Robinson, chief scientist for the orbiter's cameras at Intuitive Machines and lead author of one paper, told the AP that the impact churned the lunar surface for more than 66 miles (100 kilometers). He also said dust and rocky soil were thrown at a higher angle than expected.

These changes have practical effects. NASA said the loosened ground could affect how rover wheels interact with the surface. The Lunar Reconnaissance Orbiter Camera team's description of McGetchin crater adds that long-lived equipment on the Moon must be engineered to withstand high-velocity small particles thrown out by distant impacts.

Impact Odds and What Future Missions Can Learn

Large lunar impacts are rare but not rare enough to ignore. "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. "As such, this event constitutes a statistically rare, effectively once-in-a-lifetime observation."

Smaller hits are constant. Over more than 17 years, the orbiter team has identified at least 1,000 new impact craters and flagged about 100,000 other surface changes. The smallest craters scientists can distinguish in the orbiter's images are about 30 feet wide, made by rocks about 43 inches across, and NASA estimates that impacts at that scale produce about 140 new craters on the Moon each year.

That is the key difference from Earth. With no atmosphere to slow or burn up incoming objects, space rocks reach the lunar surface easily. For mission planners, McGetchin offers a rare real-world measurement of how often the surface is struck and how far disturbed ground can extend.

The findings have limits. The papers are peer-reviewed, but they describe a single event. The 132-year recurrence figure comes from crater production models rather than direct observation, and the cold zone was measured at one site. NASA said a future paper is expected to estimate the size and force of the object that made the crater.

The bottom line: the largest fresh crater ever found went unseen for more than a year, and it changed the ground miles beyond its rim. Its main value is practical, because it gives mission planners measured data on impact frequency and on how loose the surface can become.

What Readers Want to Know

How big is the new Moon crater?

McGetchin crater is 728 feet (222 meters) wide and 141 feet (43 meters) deep. Scientists describe it as the largest newly formed crater ever found in the solar system.

When did the impact happen?

The impact happened between April 11 and May 22, 2024, on the Moon's eastern edge. NASA says the crater was discovered on Oct. 24, 2025.

Why did no one see the impact when it happened?

It was not detected in real time. It was found later by comparing before-and-after orbiter images.

What is the cold zone?

It is an area about 4 miles wide around the crater that is about 16°F colder at night than its surroundings. The impact loosened the surrounding soil, which holds less heat.

How often do impacts this large hit the Moon?

Crater production models suggest about once every 132 years. Smaller impacts are far more common, producing about 140 craters of at least 30 feet across each year.

Does this affect future Moon missions?

NASA says loosened ground can affect how rover wheels interact with the surface, and the camera team says long-lived equipment must withstand small particles thrown out by distant impacts.

Could an impact like this happen on Earth?

Earth is struck by space rocks too, but its atmosphere slows or breaks up many of them. The Moon has no atmosphere, so rocks reach its surface far more easily.