Scientists have made an intriguing discovery on the moon, uncovering a crater larger than the Roman Colosseum that resulted from a significant impact event two years ago, initially escaping detection. This steep-sided crater, measuring 222 meters across and up to 43 meters deep, stands as the most substantial impact crater formed in recent times within our solar system.
The rarity of this event, occurring approximately once every 132 years, presents a valuable opportunity for NASA as they plan to establish a lunar base for astronauts. Described as a statistically unusual occurrence, the discovery was detailed in two studies published in the journal Science Advances.
NASA’s Lunar Reconnaissance Orbiter (LRO) first identified the crater on the moon’s near side in May 2024, following its formation by an asteroid or comet fragment. Notably, the impact was not immediately detected by telescopes on Earth or in space. Subsequent analysis of LRO’s wide-angle images revealed the crater in August 2025, with further confirmation of the finding earlier this year.
Named in honor of the late Thomas McGetchin, a former director of Houston’s Lunar and Planetary Institute, the crater showcases the moon’s rich history of impacts, including some of the largest craters in the solar system. This recent impact altered over 100 kilometers of the lunar surface, ejecting dust and rocky soil at unexpected angles, as highlighted by Mark Robinson, the lead author of one of the studies and chief scientist for LRO’s cameras at Intuitive Machines.
A separate study detected a seven-kilometer-wide cold spot surrounding the new crater, indicating a disruption of the moon’s topsoil. Co-author David Paige from the University of California, Los Angeles, likened this phenomenon to gardening, where impacts churn the regolith, the loose material covering bedrock.
The ongoing discoveries by LRO since its launch in 2009 reveal that the moon’s top layer of soil is overturned by ejected material every 80,000 years, a faster rate than previously thought. This challenges the notion that Apollo moonwalkers’ footprints would endure indefinitely, as Robinson pointed out.
Looking ahead, researchers aim to assess the risk of ejected crater material impacting NASA’s planned moon base to inform the engineering of resilient structures, mitigating potential damage concerns.