LRO discovers large new lunar crater, finds interesting thermal emission phenomenon

3 min read · reported by NASASpaceflight

Using NASA’s Lunar Reconnaissance Orbiter, a team of scientists has discovered the largest, newly formed crater ever found in the solar system. Identified during a routine data-quality check as a bright spot with a dark halo, the discovery highlights the ever-changing landscape of our celestial neighbor.

“I just stopped, dropped everything, and started looking into what that spot was,” said Robert Wagner, an image-processing specialist from Intuitive Machines, who first identified the crater when working with Lunar Reconnaissance Orbiter Camera (LROC) data. By comparing new imagery of the region with old imagery, Wagner confirmed that a new crater had formed.

Analysis of Lunar Reconnaissance Orbiter (LRO) data shows that the crater formed between April 11 and May 22, 2024, along the Moon’s eastern edge. The size of the crater suggests that the culprit — likely a comet or asteroid — was roughly the size of a three- to six-story building. The crater has officially been named McGetchin Crater after lunar scientist Tom McGetchin.

The crater itself measures approximately 222 m wide and 43 m deep, spanning more than two American football fields in length and three vertically stacked yellow school buses in depth. Scientists estimate new craters this size to appear once every century.

LROC images the Moon’s surface from an altitude of 96.5 km, allowing its three cameras to capture high-resolution black-and-white and moderate-resolution multispectral images. The instrument has been used to discover new craters, landslides, seismic faults, potential lava tubes, and even robotic landers.

When looking for changes on the lunar surface, scientists often use LROC’s Narrow-Angle Camera to detect features smaller than 9 meters across. However, teams will sometimes conduct wider searches by having LROC’s Wide-Angle Camera map vast regions of the Moon’s surface.

When Wagner discovered McGetchin on Oct. 24, 2025, he was reviewing data from LROC’s Wide-Angle Camera, stacking hundreds of before-and-after frames to highlight changes in surface color. However, Wagner’s software flags tiny shifts in lighting or shadow, creating hundreds of false alarms for Wagner to sift through. When verifying the flags generated by the software, Wagner looks for small fuzzy halos around bright points in the difference images, which normally indicate areas where regolith has been shifted around a new crater.

However, McGetchin was easier to spot than most other craters. “It was by far the most obvious impact debris pattern I’ve ever seen in one of these images,” Wagner said.

Once McGetchin had been discovered, LRO scientists used LROC’s Narrow-Angle Camera to capture sharper images of the crater, revealing its size, shape, and surroundings. The Narrow-Angle Camera images also allowed scientists to estimate the size of the object that created the crater.

Impacts from comets, asteroids, and even rocket stages are common on the Moon, where the lack of a thick atmosphere allows objects to reach the surface with little to no resistance. On Earth and other planets with thick atmospheres, incoming objects burn up due to atmospheric friction, creating “shooting stars.” However, a majority of the objects that impact the lunar surface are too small to detect.

LRO’s instruments can detect craters as small as nine meters across, typically formed by objects approximately 1.1 m wide. Scientists believe that impacts of this scale create over 100 new craters on the lunar surface every year. Throughout its 17-year mission, LRO has cataloged at least 1,000 new impact craters and more than 100,000 surface changes.

While LRO’s LROC instrument was used to discover McGetchin Crater, additional instruments aboard the spacecraft enabled scientists to investigate the crater and its surroundings further. Using LRO’s Diviner Lunar Radiometer Experiment instrument to inspect thermal emission at the crater, scientists found a 6.5 km-wide area around McGetchin that is approximately 16 degrees Fahrenheit cooler than the surrounding environment during the lunar night.

This cooling is thought to occur due to the impact dislodging and “fluffing” regolith around the crater, making it less dense and more susceptible to heat loss. The phenomenon shows how surface impacts can affect more than just the crater, providing scientists with insight into how future robotic and crewed lunar missions will fare on the surface.

Two new papers have been published in the Science Advances journal on the discovery of McGetchin, with more on the way.

The paper announcing the discovery of McGetchin can be found here.

The second paper, studying the crater with LRO’s Diviner instrument, can be found here.

Reported by NASASpaceflight. Reproduced unedited by Everything Space. View the original →