A recent discovery by scientists has revealed a massive crater on the moon, surpassing the size of the Roman Colosseum. The crater, formed two years ago due to a powerful impact that went unnoticed initially, measures 222 meters across and up to 43 meters deep, making it the largest known impact crater in the solar system from recent times.
This rare event, estimated to occur once every 132 years, is considered a significant find as NASA plans to establish a moon base for astronauts. Named after the late Thomas McGetchin, a former director of Houston’s Lunar and Planetary Institute, the crater was spotted by NASA’s Lunar Reconnaissance Orbiter (LRO) on the moon’s near side in May 2024.
The impact, caused by an incoming fragment of an asteroid or comet, eluded detection by telescopes on Earth and in space. Detailed images of the crater were captured by LRO in August 2025, with confirmation of the discovery made early the following year.
The impact churned the lunar surface over 100 kilometers, ejecting dust and rocky soil at a higher angle than expected. This discovery sheds light on the dynamic nature of the moon’s surface, with impacts serving as a way to churn the regolith, the loose material covering the bedrock.
Studies show that the moon’s top two centimeters of soil are overturned by ejected material every 80,000 years, faster than previously believed. Contrary to popular belief, even the footprints left by Apollo moonwalkers will not last forever under these conditions.
Moving forward, researchers aim to assess the risk of ejected crater material striking NASA’s future moon base to enhance structural resilience and safety measures.