Scientists have uncovered a newly formed crater on the moon, larger than the Roman Colosseum, resulting from a significant impact that went unnoticed until recently. This steep-sided crater measures 222 meters across and up to 43 meters deep, making it the largest impact crater in the solar system known to have formed in modern times.
According to researchers, such a massive event is estimated to happen only once every 132 years, making this discovery a valuable source of information as NASA plans to establish a base for astronauts on the moon. The findings were published in two studies in the journal Science Advances.
The crater was identified by NASA’s Lunar Reconnaissance Orbiter (LRO) on the moon’s near side in May 2024, following an impact by an asteroid or comet fragment. Despite escaping detection by telescopes on Earth and in space in real-time, LRO’s wide-angle images eventually revealed the crater in August 2025, with detailed pictures confirming the discovery in early 2026.
Named after the late Thomas McGetchin, a former director of Houston’s Lunar and Planetary Institute, the crater has altered a region of the moon’s surface spanning over 100 kilometers. Mark Robinson, chief scientist for the LRO’s cameras, noted that the impact ejected dust and rocky soil at a higher angle than expected.
A separate study found a seven-kilometer-wide cold spot surrounding the crater, indicating a loosening of the moon’s topsoil. Co-author David Paige likened the impact to gardening, suggesting that it churns the regolith, the loose material covering bedrock.
Robinson highlighted that the LRO’s discoveries since its launch in 2009 indicate that the moon’s top two centimeters of soil are overturned by ejected material every 80,000 years, a faster rate than previously believed. He dispelled the myth that the footprints of Apollo moonwalkers will endure forever, stating that they will likely disappear within that timeframe.
The next phase involves assessing the risk of ejected crater material reaching NASA’s proposed moon base to enhance structural integrity and minimize potential damage.