# Lunar Impact Crater Sets Solar System Record A massive asteroid created a 728-foot crater, offering rare research opportunities. - **Source:** [Popular Science](https://brifing.si/source/cc3d313a-759c-4802-b881-fc8585f35ef9) - **Published:** 2026-09-17 - **Original article:** - **On Brifing:** https://brifing.si/s/6716170a-481e-4006-90e5-e9e808efb63e ## Unprecedented lunar impact NASA's Lunar Reconnaissance Orbiter detected a 728-foot-wide crater formed by a building-sized asteroid impact - the largest fresh crater ever observed in our solar system. This event, occurring between April-May 2024 on the Moon's eastern edge, represents a once-in-a-century opportunity to study large-scale impact physics. The crater dwarfs typical 30-foot formations created by coffee-table-sized asteroids that hit the Moon 140 times annually. ## Discovery through pixel analysis Image specialist Robert Wagner identified the crater on October 24, 2025 during routine LRO data review, spotting an unusual bright circle with a dark halo. Unlike automated systems that generate false positives, Wagner manually examined pixel-level regolith disturbances to confirm the impact. The discovery adds to LRO's catalog of 1,000+ craters and 100,000 surface changes documented since 2009, though this find stood out immediately for its scale. ## Thermal evidence of disturbance Follow-up scans from LRO's Diviner instrument revealed a four-mile-wide area around McGetchin crater (named after lunar scientist Tom McGetchin) with nighttime temperatures 16°F cooler than surroundings. This thermal signature confirms significant regolith disruption, where impact-loosened soil retains less heat. The crater's depth measures 141 feet, with debris patterns Wagner described as the most obvious he's ever observed in lunar images. ## Scientific significance The McGetchin crater provides astronomers their first chance to study the immediate aftermath of a massive impact in high resolution. Typical lunar craters form from smaller, more frequent strikes, making this event uniquely valuable for understanding large asteroid physics. Researchers will use LRO's Narrow-Angle Camera to examine the crater at 3-feet-per-pixel resolution, with findings to be published in upcoming studies. ## Impact detection methodology LRO's crater identification process involves comparing before/after images with software highlighting shadow changes, though this generates many false positives. Wagner's manual verification through regolith pattern analysis proved crucial for confirming this exceptional event. The discovery demonstrates how human expertise complements automated systems in identifying rare astronomical phenomena. ## Ongoing research directions Scientists continue analyzing the impactor's exact size and collision force. The crater's preservation offers an ideal natural laboratory, as lunar conditions maintain impact features undisturbed by weather or erosion. Future studies may reveal how often such large impacts occur and their potential effects on lunar geology and future human exploration efforts. ## Technological capabilities The discovery showcases LRO's continued value 16 years after launch, with its suite of cameras and thermal instruments proving capable of detecting both microscopic changes and massive events. Its Narrow-Angle Camera's high resolution will be critical for detailed crater analysis, building on previous findings about lunar surface evolution and impact frequency. ## Planetary defense implications While this impact posed no Earth threat, studying such events improves our understanding of large asteroid behavior - knowledge vital for planetary defense. The McGetchin crater serves as a benchmark for modeling potential Earth impacts, helping scientists refine predictions about collision frequencies and effects for similarly sized asteroids. ## Sources covering this story - https://www.popsci.com/science/new-moon-crater-photos/ — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._