Scientists have identified a massive crater on the moon, larger than the Roman Colosseum, resulting from a powerful impact that went unnoticed two years ago. Measuring 222 meters wide and up to 43 meters deep, this crater is the largest known recent impact site in the solar system.
According to researchers, such significant events are rare, occurring approximately once every 132 years. The discovery of this crater holds valuable information as NASA plans to establish a lunar base for astronauts. The scientists highlighted the rarity of this event in a study published in the journal Science Advances.
The crater was first spotted by NASA’s Lunar Reconnaissance Orbiter (LRO) on the moon’s near side in May 2024, following an impact from an asteroid or comet fragment. Despite evading detection by telescopes on Earth and in space, LRO’s wide-angle images eventually revealed the crater in August 2025, with confirmation of the discovery early this year.
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 expected, as noted by Mark Robinson, the chief scientist for LRO’s cameras.
Another study found a seven-kilometer-wide cold spot surrounding the new crater, indicating a disturbance in the moon’s topsoil. Co-author David Paige likened this phenomenon to gardening, suggesting impacts as a way to rejuvenate the lunar regolith, the loose material covering the bedrock.
Robinson highlighted LRO’s continuous discovery of craters, revealing that the moon’s top two centimeters of soil are overturned by ejected material every 80,000 years, a faster rate than previously estimated. Contrary to popular belief, the footprints of Apollo moonwalkers will not last indefinitely under such conditions.
Moving forward, researchers aim to assess the risk of ejected crater material impacting NASA’s lunar base, enabling engineers to reinforce structures and mitigate potential damage.