NASA Spots Record-Breaking New Crater on the Moon
NASA scientists have identified the largest newly formed impact crater ever documented in the solar system, a 728-foot-wide scar on the Moon's eastern edge named McGetchin crater. The crater formed sometime between April 11 and May 22, 2024, when a comet or asteroid struck the lunar surface, but it wasn't until a routine data-quality check in May 2024 that NASA's Robert Wagner noticed an unusually bright patch surrounded by a dark halo on a global map of the Moon.
"I just stopped, dropped everything, and started looking into what that spot was," Wagner said in a NASA blog post. By comparing before-and-after images from NASA's Lunar Reconnaissance Orbiter (LRO), Wagner confirmed the feature was a fresh impact crater. Further observations and higher-resolution images confirmed the discovery earlier this year.
The crater, named after lunar scientist Tom McGetchin, measures about 222 meters (728 feet) across and 43 meters (141 feet) deep. It is roughly three times wider than the previous record-holder for a newly formed crater found by LRO. The impact also flung dust and broken rock across more than 120 kilometers (75 miles) of the lunar surface, according to a study led by Mark Robinson at Intuitive Machines.
A Once-in-a-Lifetime Observation
Scientists estimate that an impact capable of producing a crater this size occurs on the Moon only about once every century—or even longer. "This event constitutes a statistically rare, effectively once-in-a-lifetime observation," researchers wrote in studies published in the journal Science Advances. The incoming object is thought to have been the size of a three- to six-story building.
Why This Matters: A Baseline for Lunar Geology
The discovery offers an unprecedented opportunity to study how impacts modify the lunar surface. Most lunar craters are extremely old and have been altered by later impacts and exposure to space. McGetchin is different because researchers have before-and-after images that allow direct comparison of the same region.
"Cratering is probably the most common process that happens in the solar system, so we spend a lot of time trying to understand how a new crater will modify a surface and watching that degrade over time," said Tyler Powell at Johns Hopkins University in Maryland. "Having a baseline for a pristine crater that can serve as our calibration point for how these processes start is really incredible."
Powell's team measured surface temperatures around the crater and found a cold spot about 7 kilometers wide that is several degrees colder than the surrounding area during the lunar night. These cold spots form when lunar dust fluffs up after an impact, cooling faster after sunset. The findings could aid future exploration by helping scientists understand the properties of the lunar surface.
A Rapidly Changing Moon
The discovery also highlights how much the Moon still changes. LRO, which has been orbiting the Moon for more than 17 years, has identified at least 1,000 new impact craters and flagged 100,000 more surface changes. Without an atmosphere to slow incoming space rocks, even small impacts can leave visible marks. Scientists estimate that rocks about 43 inches wide create roughly 140 new craters across the Moon each year.
Broader Implications for Planetary Science
The McGetchin crater is located near the boundary between the Moon's darker basalt-covered plains and its brighter highlands. Researchers say this setting could allow future missions to examine how the same impact affected different types of terrain.
The discovery underscores the value of long-term orbital missions like LRO, which continue to provide data that lead to unexpected findings. As scientists study McGetchin crater over time, it will serve as a natural laboratory for understanding impact processes not only on the Moon but on other airless, cratered bodies throughout the solar system.
"If we're trying to send rovers or astronauts or build things on the Moon, we want to understand the properties of the surface," Powell said. "And watching a huge new crater form and change over time is one of the best remote probes of the surface we've ever had."
With the exact impact date and the nature of the impactor—comet or asteroid—still uncertain, McGetchin crater stands as a reminder that even our closest celestial neighbor can still surprise us.
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