In the spring of 2024, a comet or asteroid the size of a mid-rise building struck the Moon, carving a crater 728 feet wide into its ancient surface — an event of this scale occurring only once every century or so. The impact went unwitnessed and unnoticed until NASA scientist Robert Wagner, reviewing archival photographs from the Lunar Reconnaissance Orbiter in late 2025, recognized the unmistakable signature of something new. Named McGetchin, this crater reminds us that the solar system is not a finished place — that even familiar celestial neighbors are still being quietly, violently remade.
NASA Spots Rare Lunar Impact Crater, a Once-a-Century Event
An impact this size happens roughly once every 132 years.
Mark
So NASA found a crater that formed in 2024, but didn't notice it until October 2025? How does that even happen?
Mimi
The moon is huge, and the Lunar Reconnaissance Orbiter takes pictures of vast areas. Wagner was comparing archived images—before-and-after shots—and spotted the difference. It's like noticing a new pothole on a road you drive every day, except the road is the entire moon.
Luke
But we should be clear: no one was actively monitoring for new impacts in real time. The discovery was accidental, a side effect of routine imaging. We don't have continuous surveillance of the lunar surface.
Mark
And this crater is the biggest one formed recently?
Mimi
The biggest modern impact in our solar system, yes. But not the biggest crater on the moon overall. The South Pole-Aitken Basin is enormous—1,550 miles across. McGetchin is 728 feet wide. The difference is that McGetchin is fresh, and it's rare. Impacts this size happen maybe once a century.
Luke
The estimate is "once every 132 years or so." That's based on models and historical observation, not a perfect count. It's the best number we have, but it's still an estimate.
Mark
What's with the cool zone around it?
Mimi
Scientists found a four-mile-wide area that's about 16 degrees cooler at night. The impact probably disrupted the surface in a way that changes how heat escapes. It's unusual, and it's one reason McGetchin will probably be studied intensively.
Luke
But we don't fully understand why yet. That's still an open question.
Mark
Will we learn more?
Mimi
Almost certainly. An impact this rare is a gift to lunar science. Expect a lot of papers.
Le Pouls
- A building-sized space rock struck the Moon undetected in spring 2024, leaving a 728-foot-wide, 141-foot-deep wound that sat undiscovered for over a year.
- The rarity of the event sharpens its significance — impacts capable of producing a crater this large happen roughly once every 132 years, making McGetchin a once-in-a-lifetime scientific find.
- NASA scientist Robert Wagner caught the crater almost by chance, comparing before-and-after orbital photographs until the unmistakable outline of something new emerged from the familiar terrain.
- NASA redirected the Lunar Reconnaissance Orbiter to capture detailed close-up images in December 2025, confirming the crater's structure and the scale of the impact.
- A four-mile zone surrounding the crater runs 16°F cooler at night than the surrounding surface — a thermal anomaly that remains unexplained and is already drawing intense scientific scrutiny.
In the spring of 2024, a comet or asteroid the size of a mid-rise building struck the Moon, carving a crater 728 feet wide into its ancient surface — an event of this scale occurring only once every century or so. The impact went unwitnessed and unnoticed until NASA scientist Robert Wagner, reviewing archival photographs from the Lunar Reconnaissance Orbiter in late 2025, recognized the unmistakable signature of something new. Named McGetchin, this crater reminds us that the solar system is not a finished place — that even familiar celestial neighbors are still being quietly, violently remade.
Sometime in the spring of 2024, a comet or asteroid roughly three to six stories tall struck the Moon, carving a crater 728 feet wide and 141 feet deep into the lunar surface. No one witnessed the impact. The scar sat unnoticed for more than a year until NASA scientist Robert Wagner, reviewing images from the Lunar Reconnaissance Orbiter in October 2025, spotted something that didn't belong — a fresh mark where none had been before. By comparing photographs taken before and after the event, he confirmed the Moon had been struck sometime between mid-April and late May 2024. The crater was named McGetchin, after scientist Tom McGetchin.
What makes the discovery remarkable is not its size relative to the Moon's ancient scars — the South Pole-Aitken Basin stretches 1,550 miles across — but its recency. Most visible lunar craters are relics of the early solar system. An impact capable of producing a crater the size of McGetchin happens only once every 132 years. NASA responded by redirecting the orbiter back to the site, and in December 2025, detailed narrow-angle images confirmed the crater's structure and the full extent of the disturbance.
Researchers have already found something unexpected: a zone roughly four miles wide surrounding the impact runs about 16°F cooler at night than the surrounding lunar surface. The source of this thermal anomaly is not yet understood, but it suggests the impact altered how heat radiates from the ground in ways that will take years to fully explain. Scientists expect McGetchin to become one of the most closely studied craters on the Moon — a rare, still-fresh window into what happens when a cosmic object meets an airless world.
Sometime in the spring of 2024, a space rock the size of a mid-rise building struck the moon. No one saw it happen. The impact left a crater 728 feet across and 141 feet deep—a scar that would sit unnoticed on the lunar surface for more than a year until a NASA scientist happened to look at the right photographs at the right moment.
Robert Wagner, a scientist at NASA, was reviewing images captured by the Lunar Reconnaissance Orbiter in October 2025 when he noticed something that shouldn't have been there. The orbiter's wide-angle camera had been photographing the same stretches of lunar terrain for years, building up a library of before-and-after snapshots. Wagner compared pictures taken before the impact with newer ones and saw the unmistakable mark of a fresh crater. The object that made it—a comet or asteroid somewhere between three and six stories tall—had struck sometime between mid-April and late May 2024. The crater was officially named McGetchin, after the scientist Tom McGetchin.
What makes this discovery significant is not its size relative to other lunar features. The moon is scarred with far larger craters. The South Pole-Aitken Basin, the largest crater on the moon, stretches 1,550 miles across. But McGetchin represents something rarer: a modern impact of substantial scale. Most lunar craters visible today are ancient, relics of the early solar system. Most recent impacts are small, barely worth noting. An impact the size of McGetchin—capable of excavating a crater 728 feet wide—happens roughly once every 132 years. The last time something this large struck the moon, most people alive today had not yet been born.
Wagner's discovery prompted NASA to direct the Lunar Reconnaissance Orbiter back to the site. In December 2025, the orbiter's narrow-angle camera captured detailed images of the fresh crater, showing its structure and the surrounding terrain. Those photographs confirmed what the initial comparison had suggested: the moon had been struck by something substantial, and the evidence was now in hand.
The crater itself is not the only thing drawing scientific attention. Researchers who have already begun studying McGetchin found something unexpected in the area around it. A zone roughly four miles wide surrounding the impact site runs about 16 degrees Fahrenheit cooler at night than the surrounding lunar surface. The reason for this thermal anomaly is not yet fully understood, but it suggests that the impact disturbed the moon's surface in ways that altered how heat radiates from the ground after sunset. That mystery alone is likely to fuel years of research. Given how seldom impacts of this magnitude occur, scientists expect McGetchin to become one of the most studied craters on the moon, a natural laboratory for understanding what happens when a building-sized object collides with an airless world at cosmic speeds.
Citations marquantes
NASA scientist Robert Wagner identified the new crater by comparing before-and-after images from the Lunar Reconnaissance Orbiter— NASA
Envie de l'histoire complète ?
Lire l'original sur Engadget ↗
Science & Space