Scientists have identified a massive crater on the moon, larger than the Roman Colosseum, resulting from a significant impact two years ago that went unnoticed initially. The crater, measuring 222 meters across and up to 43 meters deep, is the most substantial impact crater formed in recent times within the solar system.
This rare event, occurring approximately once every 132 years, provides valuable insights as NASA prepares to establish a base for astronauts on the moon. The discovery, detailed in two studies published in Science Advances, is described as a statistically uncommon and unique observation.
The Lunar Reconnaissance Orbiter (LRO) detected the crater on the moon’s near side in May 2024, shortly after its formation by an asteroid or comet fragment. Despite evading detection by telescopes on Earth and in space at the time, LRO’s wide-angle images eventually revealed the crater in August 2025, with more detailed pictures confirming the finding in early 2026.
Named after the late Thomas McGetchin, a former director of Houston’s Lunar and Planetary Institute, the crater altered over 100 kilometers of the lunar surface. The impact resulted in the expulsion of dust and rocky soil at a higher angle than anticipated, according to Mark Robinson, the lead author of one of the studies and the chief scientist for LRO’s cameras at Intuitive Machines.
Another study identified a cold spot spanning seven kilometers around the new crater, indicating a disturbance in the moon’s topsoil. Co-author David Paige from the University of California, Los Angeles, likened the impact to gardening, noting how impacts could churn the regolith, the loose material above bedrock.
Robinson highlighted that LRO’s continuous discoveries since its launch in 2009 suggest that the moon’s top two centimeters of soil are overturned by ejected material every 80,000 years, a faster rate than previously assumed. This challenges the belief that the footprints of Apollo moonwalkers will endure indefinitely, as they are expected to vanish within that timeframe.
The next phase involves assessing the risk of ejected crater material striking NASA’s planned moon base to fortify structures and minimize potential damage.