NASA Discovers Rare ‘Once-in-a-Century’ Moon Crater

A massive, recently-formed crater on the Moon measuring 222 meters wide has been discovered by Robert Wagner using the Lunar Reconnaissance Orbiter, according to a study published in Science Advances. Scientists estimate that such an impact from a building-sized comet or asteroid occurs only once in a century or longer.

## Discovering the Largest New Solar System Crater

A routine data-quality check led to the landmark find on the Moon’s eastern edge. Robert Wagner, an image-processing specialist from Intuitive Machines working with NASA’s Lunar Reconnaissance Orbiter Camera system, spotted an unusual bright spot circled by a dark halo while scanning a giant Moon map.

“I just stopped, dropped everything, and started looking into what that spot was,” Wagner said.

By comparing before and after images captured by the Lunar Reconnaissance Orbiter, Wagner confirmed the feature was the largest newly formed crater ever discovered in the solar system. The spacecraft, which has been circling the Moon since 2009, uses seven instruments to map topography, surface composition, temperature, and radiation.

Officially named McGetchin after pioneering lunar scientist Tom McGetchin, the crater formed sometime between April 11 and May 22, 2024. According to NASA, the impact was triggered by a comet or asteroid measuring the size of a building three to six stories high.

## Dimensions and Impact Physics on an Airless Moon

The resulting cavity spans 728 feet wide, which equals the length of two football fields. At 141 feet deep, the crater could comfortably fit three vertically stacked yellow school buses, according to NASA figures.

Scientists estimate that an impact of this magnitude happens on the Moon about once in a century or even longer. For comparison, the smallest craters visible in Lunar Reconnaissance Orbiter images measure about 30 feet wide—roughly the length of a three-story building laid on its side—and are carved by rocks about 43 inches wide, or the size of a monster-truck tire.

Unlike Earth, the Moon has virtually no atmospheric layer. Space debris and meteoroids reach the lunar surface without slowing down or burning up. While the spacecraft’s team has identified at least 1,000 new impact craters and flagged 100,000 other surface changes over a 17-year mission, most of those are created by microscopic projectiles that leave holes too small for orbital cameras to resolve.

## Thermal Anomalies and Surface Alterations

The physical changes caused by the McGetchin impact extend far beyond the crater walls. Following the discovery, scientists analyzed data from the Lunar Reconnaissance Orbiter’s thermal instrument, known as Diviner.

Researchers found a four-mile-wide area surrounding the crater that is about 16 degrees Fahrenheit cooler at night than its surrounding terrain. According to a second study published in Science Advances, the impact fluffs up the lunar regolith around the crater, rendering it less dense and less capable of retaining heat.

Understanding these real-time geological shifts helps researchers map dynamic lunar landscapes. That data directly supports future crewed missions to the Moon currently planned by both the United States and China, as surface modifications like fluffed regolith can alter how rover wheels and equipment interact with the terrain.