NASA finds the biggest fresh crater ever spotted on the moon, and nobody noticed the impact happen

[Daz92]

NASA scientist Robert Wagner made an accidental discovery back in October 2025 that has only now been fully confirmed and named, spotting an unusually large bright spot circled by a dark halo while reviewing before and after photographs taken by the Lunar Reconnaissance Orbiter. What he had stumbled onto turned out to be the largest newly formed crater ever recorded anywhere in the solar system, now officially named McGetchin crater after pioneering lunar scientist Tom McGetchin.

The numbers involved are genuinely striking once you put them in context. McGetchin crater measures 222 metres across and 43 metres deep, roughly comparable in footprint to the Roman Colosseum, and it dwarfs the previous record holder discovered by the same Lunar Reconnaissance Orbiter a decade earlier by a factor of three. Whatever hit the moon to create a hole this size was no small pebble, NASA's assessment points to a comet or asteroid roughly the size of a three to six storey building slamming into the lunar surface.

What makes the story stranger is the timing gap between the actual impact and its discovery. Researchers were able to narrow the strike down to a window between April 11 and May 22 2024, meaning this crater sat there completely unnoticed on the moon's surface for well over a year before anyone on Earth realised it existed. Wagner confirmed his initial hunch by hunting down small fuzzy halos around pixel wide bright points in the imagery, the telltale signature of ejected lunar soil splashing outward from a fresh impact site.

The scale of the disturbance the impact caused is almost as remarkable as the crater itself. NASA reports that the strike churned up the lunar surface across more than 100 kilometres, with dust and soil thrown outward at unexpectedly high angles compared to what modelling would typically predict for an impact of this size. That kind of far reaching disturbance from a single strike gives planetary scientists a genuinely rare real world data point for refining impact models used across the wider field.

NASA has described the whole event as a statistically rare, effectively once in a lifetime observation, estimating that an impact of this scale on the moon happens roughly once every 132 years. Given how much of the moon's surface remains unmonitored at any given moment, the fact that this was caught at all, albeit well over a year after it actually happened, says a lot about how much lunar surveillance capability has improved even as it also highlights just how much can still slip past detection in real time.

Asteroid The Size Of Six Storey Building Crashed Into Moon In Once In A Lifetime Moment Says Nasa 13588849news.sky.com

[Northern Nicola]

The idea that a crater this size sat there completely unnoticed for over a year before anyone spotted it is honestly the most unsettling part of this story. We talk a lot about tracking near earth asteroids but apparently we are not even reliably catching the ones that actually hit somewhere close by.

[Cyclops46]

222 metres across and three times bigger than the previous record holder is a genuinely huge jump for a discovery gap of only ten years between the two events. Either impacts of this scale are more common than the once every 132 years estimate suggests, or our detection methods have just gotten a lot better very recently.

[Reacher Mitchell]

A three to six storey building sized object hitting the moon and creating a crater the size of the Colosseum puts into perspective just how much kinetic energy is involved even in what counts as a relatively modest impact by cosmic standards. Makes you think differently about the near earth asteroid tracking programs and why they matter.