Scientists have identified a massive crater on the moon that dwarfs the Roman Colosseum, formed by a powerful impact two years ago that was initially missed by observation systems. The newly discovered hole measures approximately 728 feet across and reaches depths of 141 feet, making it the largest known impact crater in the solar system carved out during recent times.
The crater is named after Thomas McGetchin, the former director of Houston’s Lunar and Planetary Institute. It is three times larger than the previous record-holder found by NASA’s Lunar Reconnaissance Orbiter (LRO) a decade ago. Events of this scale are estimated to occur roughly once every 132 years, providing researchers with a rare opportunity to study fresh geological data as NASA plans its future crewed lunar base.
Researchers published their findings Wednesday in two studies within the journal Science Advances. “This event constitutes a statistically rare, effectively once-in-a-lifetime observation,” the scientists wrote.
NASA’s LRO detected the crater on the moon’s near side sometime between April 11 and May 22, 2024. The impact occurred when an asteroid or comet fragment, estimated to be the size of a three- to six-story building, struck the surface. The strike was not captured in real-time by telescopes on Earth or in space.
Although the LRO captured wide-angle images of the area, the discovery was not made until August 2025 due to the volume of data. Detailed images taken last fall and confirmation early this year solidified the find.
Mark Robinson, chief scientist for the LRO’s cameras at Intuitive Machines, noted that the impact churned the lunar surface for more than 66 miles. Dust and rocky soil were ejected at higher angles than anticipated. In a separate study, David Paige of the University of California, Los Angeles, identified a 4-mile-wide cold spot around the crater, suggesting the loosening of the moon’s topsoil.
“We’re now thinking of impacts as a way to garden the regolith — churning the sediments and putting stuff above that’s usually below the surface,” Paige said.
Since its launch in 2009, the LRO has provided close-up views of the lunar surface, revealing that the moon’s top inch of soil is overturned every 80,000 years—faster than previously believed. Robinson stated that this constant turnover means Apollo astronauts’ footprints will “definitely be long gone” within that timeframe.
Engineers will now use this data to assess the risk of future ejecta striking the planned lunar base, helping them design structures capable of withstanding such impacts.
Seems odd that we detected it in 2024 but didn’t confirm until early 2025. Data overload must be real.
This ‘gardening’ analogy is brilliant. Churning regolith for science and construction planning is a smart pivot.
I wonder if future astronauts will need armor plating on their habitat roofs to survive these impacts.
Wait, so Apollo footprints are already gone? That timeline seems surprisingly short given how stable the moon looks.
Fascinating! It’s wild to think the Colosseum-sized impact was missed by telescopes until two years later.