Discovery of the largest modern impact crater on the moon's surface

The moon's surface witnessed a violent impact with a comet or asteroid, and still bears a massive scar proving it happened.

It is estimated that the space rock was the size of a building, ranging from 3 to 6 stories high, and collided with the eastern edge of the moon two years ago, between April 11 and May 22, 2024, although researchers did not notice the collision at the time.

The impact left a crater 222 meters wide, slightly more than the length of two football fields, and 141 meters deep, enough to put three school buses on top of each other.

Scientists said that this lunar feature represents the largest newly formed crater found in the solar system since humans began observing such phenomena, according to a study published in the journal Science Advances on Wednesday.

“Models of crater formation indicate that an impact of this size is expected to occur only once every 132 years on the Moon,” the study authors wrote. “Therefore, this event constitutes a statistically rare observation and can be considered a once-in-a-lifetime event.”

The study's authors named this feature "McGeachin Crater" in honor of Dr. Thomas McGeachin, the late lunar scientist from the Apollo program, who contributed to enhancing understanding of the phenomenon of crater formation resulting from impacts on the Moon.

Before this discovery, the largest modern impact trace found on the Moon was about 70 meters in diameter.

Unlike Earth, the surface of the Moon is full of craters, because it does not have a protective atmosphere to protect it from the constant bombardment of space rocks over billions of years.

Discovering a new crater among the huge number of craters that already exist may seem like searching for a needle in a haystack, but a NASA orbiter, which has been orbiting the moon for more than 17 years, helped scientists identify a large bright spot surrounded by a dark halo.

Scientists used data from the Lunar Reconnaissance Orbiter to study the impact of the crater and the extent of the impact of the collision on the surrounding area.

The results revealed that the Moon, which is a high-priority destination for NASA and other space agencies within the framework of sustainable human exploration plans, is still witnessing significant collision activity that should be monitored, because it may pose a threat to humans and potential infrastructure on its surface.

"I'm amazed almost every day when I come to work and look at the latest images of the Moon, even after 17 years of operation," Mark Robinson, study co-author and principal investigator for the Lunar Reconnaissance Orbiter camera at Texas-based space company Intuitive Machines, wrote to CNN.

The Lunar Reconnaissance Orbiter, known as LRO, has been one of the most prominent tools for scientific work since its launch in 2009, using seven instruments to prepare maps of the Moon’s temperature, surface composition, topography, and radiation levels. The spacecraft rotates in an orbit that extends from one pole to another, and uses two cameras to take pictures from a height of about 97 kilometers above the surface of the moon.

As a result, the spacecraft also enabled scientists to detect at least 1,000 new impact craters and 100,000 other changes on the surface, including landslides and even landers that crashed onto the moon's surface.

Very small space rocks, which are difficult to see, cause a large number of craters and craters scattered on the moon. About 140 new craters appear on the moon annually, some of which may reach a diameter of about 9 meters, as a result of the collision of space rocks about 109 centimeters wide.

But every few years, as scientists examine detailed LRO images, they look for larger features by comparing new lunar maps with older versions.

Study co-author Robert Wagner, an image processing specialist at Intuitive Machines working with Lunar Reconnaissance Orbiter camera data, discovered McGeachin Crater on October 24, 2025, while examining before-and-after images taken by the LRO spacecraft, which help highlight unusual changes in dark or bright areas on the surface.

“I immediately stopped and started looking into what that spot was,” Wagner said in a statement.

This process is not easy, as the software used by LRO scientists detects every change related to lighting or shadows. The team reviews each signal and tests whether it is real or just a false alarm, according to Robinson.

But the McGeachin crater clearly caught Wagner's attention.

To confirm the discovery, the team used sharp, close-up images taken by the rover's narrow-angle camera, which also enabled researchers to measure the crater's shape, size, and impact on the surrounding terrain.

A separate team of scientists analyzed data from the "Diviner" thermal device on the "LRO" spacecraft, and the analysis revealed an area extending 6.4 kilometers wide around the crater, which is 9 degrees Celsius colder at night compared to the rest of the region.

The team published its results in a second research paper in the journal Science Advances, also on Wednesday.

"Previous Diviner observations have shown that modern lunar craters from impacts are often associated with what are known as 'cold spots,'" Tyler Powell, the study's lead author and a planetary scientist and postdoctoral researcher at the Johns Hopkins University Applied Physics Laboratory, wrote to CNN.

“The widespread extent of these regions suggests that impacts can modify the surface at distances far beyond the crater,” Powell said. “We are very fortunate that they formed during the lifetime of the LRO mission, giving us the ability to monitor the region before and after impact.”

Scientists believe that these cold spots occur as a result of disturbances in the moon’s surface, “leading to the formation of a more fragile layer that is less able to retain heat throughout the night,” according to Powell.

Robinson said that tracking changes occurring on the surface of the Moon is crucial to determining the rate at which space rocks collide with the Moon, as well as to understand how asteroids break up when they collide with a rocky body.

He added that studying the new craters may provide information about the processes that occur at the moment of impact.

Understanding the rate and magnitude of these impacts on the Moon could be crucial for future planning for a lunar base and other facilities as NASA's Artemis program works to return humans to the lunar surface for long-term exploration.

Impact craters also contributed to shaping the surfaces of planets and rocky moons throughout our solar system, said Jeff Andrews-Hanna, a professor at the University of Arizona's Lunar and Planetary Laboratory, who was not involved in either study.

"An impact like this is supposed to be rare on the Moon, but rare events do happen. The object that caused this crater was probably close to the size of the Chelyabinsk meteorite that exploded over Russia," Andrews-Hanna wrote to CNN, referring to the asteroid that entered the Earth's atmosphere over the Russian city of Chelyabinsk in 2013, which was between 17 and 20 meters in size.

The asteroid exploded in the air, releasing approximately 20 to 30 times more energy than the atomic bomb dropped on Hiroshima, and was brighter than the sun. Fragments of the space rock damaged more than 7,000 buildings and injured more than a thousand people.

"If an object like this had managed to pass through our atmosphere and hit the Earth's surface, it wouldn't have been catastrophic, but we certainly would have noticed it," Andrews-Hanna said. "Events like this remind us how fragile we are, and the importance of cataloging and tracking near-Earth asteroids, because they may collide with Earth in the future."