Scientists have identified a massive crater on the moon, larger than the Roman Colosseum, resulting from a significant impact that occurred two years ago without initial detection. This steep-sided crater measures 222 meters across and up to 43 meters deep, ranking as the largest known recent impact crater in the solar system.
Such a rare event, estimated to happen once every 132 years, presents valuable insights as NASA plans to establish a lunar base for astronauts. The discovery, detailed in two studies published in the journal Science Advances, is described as a statistically uncommon observation.
The crater, named after Thomas McGetchin, was spotted on the moon’s near side by NASA’s Lunar Reconnaissance Orbiter (LRO) in May 2024, shortly after its formation by an asteroid or comet fragment. Notably, the impact went unnoticed by telescopes on Earth and in space.
Mark Robinson, chief scientist for LRO’s cameras at Intuitive Machines, noted that the impact spanned over 100 kilometers on the lunar surface, ejecting dust and rocky soil at unexpected angles. Another study revealed a seven-kilometer cold spot around the crater, indicating a disturbance in the moon’s topsoil akin to gardening.
Robinson highlighted that the moon’s top two centimeters of soil are overturned by ejected material every 80,000 years, a faster rate than previously believed. This challenges the notion that Apollo moonwalkers’ footprints would endure indefinitely, as they are likely to disappear within that timeframe.
Future efforts will focus on assessing the risk of ejected crater material posing a threat to NASA’s lunar base, informing engineers on structural reinforcement to mitigate potential damage.