Researchers have uncovered a massive crater on the moon, larger than the Roman Colosseum, formed from a powerful impact that occurred two years ago, undetected initially. This steep-sided crater, measuring 222 meters across and up to 43 meters deep, is the largest known impact crater in the solar system created in recent history.
Such an event is estimated to happen only once every 132 years, providing valuable insights for NASA’s upcoming moon base construction for astronauts. The discovery, detailed in two studies published in Science Advances, is considered a rare and significant observation by scientists.
NASA’s Lunar Reconnaissance Orbiter (LRO) identified the crater on the moon’s near side in May 2024, following its formation by a fragment from an asteroid or comet. The impact went unnoticed by Earth-based and space telescopes. The crater, named after Thomas McGetchin, the former director of Houston’s Lunar and Planetary Institute, was confirmed earlier this year after LRO’s detailed imaging.
The moon’s surface, already marked with ancient impact craters, including one spanning over 2,400 kilometers, underwent significant changes due to this recent impact. The debris scattered over 100 kilometers, with dust and rocky soil ejected at unexpected angles. Mark Robinson, the chief scientist for LRO’s cameras at Intuitive Machines and lead author of one study, highlighted the impact’s unique characteristics.
A separate study revealed a seven-kilometer-wide cold spot surrounding 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’s effects to gardening, altering the moon’s regolith layers.
The ongoing discoveries by LRO since its launch in 2009 suggest that the moon’s top two centimeters of soil are overturned by ejected material every 80,000 years, faster than previously thought. Robinson dismissed the notion of lasting footprints from Apollo missions, stating they would erode within that timeframe.
The next phase involves assessing the risk of ejected crater material impacting NASA’s future moon base to enhance structural resilience. This risk assessment will aid engineers in fortifying structures against potential damage.