Asteroid the size of a 6-story building hit the Moon, created 728-foot crater; NASA says such impacts happen once a century

NASA has discovered a remarkably large new crater on the Moon that was created when a comet or asteroid roughly the size of a three- to six-story building slammed into the lunar surface.

The newly identified crater, officially named McGetchin after pioneering lunar scientist Tom McGetchin, formed on the eastern edge of the Moon sometime between April 11 and May 22, 2024.

The impact carved out a crater about 728 feet (222 metres) wide and approximately 141 feet (43 metres) deep. NASA said the crater stretches roughly the length of two football fields and is deep enough to accommodate three yellow school buses stacked vertically.


Scientists estimate that an impact large enough to create a crater of this size occurs on the Moon about once every century or even less frequently.

How NASA discovered the new crater on the Moon

The discovery was made using data from NASA's Lunar Reconnaissance Orbiter (LRO), which has been studying the Moon from orbit for nearly 17 years.

Robert Wagner, an image-processing specialist from Intuitive Machines who works with data from the Lunar Reconnaissance Orbiter Camera (LROC), was examining a massive map of the lunar surface when he noticed something unusual.

An unusually large bright spot surrounded by a dark halo stood out from the surrounding landscape. The pattern suggested that the lunar surface had recently been disturbed.

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

Wagner used LROC's Wide-Angle Camera, which provides broad views of the lunar surface, to compare images taken before and after the suspected impact.

He used software to stack hundreds of images and identify changes in the landscape. Areas that remained unchanged appeared gray, while changes showed up as bright or dark patches.

The method, however, produces numerous false alarms because changes in lighting and shadows can look similar to actual surface disturbances. Researchers therefore have to manually examine potential impact sites.

New craters can often be identified by a bright point surrounded by a faint halo of material, created when lunar soil, or regolith, is blasted outward by an impact.

McGetchin was different.

Spanning hundreds of pixels in the Wide-Angle Camera images, the impact debris pattern was unusually prominent.

“It was by far the most obvious impact debris pattern I’ve ever seen in one of these images,” Wagner said.

LRO cameras revealed the crater's size

After identifying the possible impact site, researchers examined higher-resolution images from LRO's Narrow-Angle Camera.

Unlike the Wide-Angle Camera, which provides a much broader view, the Narrow-Angle Camera can capture the lunar surface at a resolution of roughly 3 feet per pixel.

When LRO subsequently passed over the site, the higher-resolution images provided a much clearer view of McGetchin.

The images allowed scientists to determine the crater's size, shape and surrounding impact debris, while also providing clues about the force of the collision.

Researchers used the observations to estimate the size of the object that struck the Moon and the energy released during the impact. More detailed analysis of the impactor is expected to be published separately.

The discovery was reported by researchers in Science Advances.

Why does the Moon keep getting hit by asteroids?

The Moon is constantly exposed to impacts from asteroids, meteoroids and other space debris.

One major reason is the Moon's lack of a substantial atmosphere.

On Earth, many small space rocks burn up or break apart while passing through the atmosphere. The Moon has no comparable atmospheric shield, allowing incoming objects to reach its surface directly.

Most lunar impacts are far smaller than the one that produced McGetchin crater.

NASA researchers can identify craters as small as about 30 feet across in images from LRO. Such craters can be produced by objects roughly 43 inches wide, approximately the diameter of a monster-truck tire.

Scientists estimat