NASA’s LRO found a rare 222-meter lunar crater. Explore what caused McGetchin crater and why the surrounding ground cools faster at night.
A natural object struck the Moon and excavated a crater about 222 meters across, leaving a fresh scar called McGetchin. The impactor was an asteroid or comet; its exact identity has not been established. NASA’s September 2026 report describes a rare opportunity to study a recently formed crater, rather than an impact that happened this week.
The collision occurred between April 11 and May 22, 2024. Its significance goes beyond the hole: observations show that surrounding ground changed over a much wider area. The story combines visible-light images, a constrained formation window and temperature measurements, allowing scientists to investigate how one impact remodels an airless surface.
Image: NASA Goddard/Intuitive Machines. Actual LRO Narrow-Angle Camera view from December 5, 2025; identifying text added without changing the terrain.
What caused McGetchin crater, and how unusual is it?
The simplest supported explanation is a natural impact. NASA describes the incoming body as a comet or asteroid, while its Astronomy Picture of the Day estimates a size of roughly 10–20 meters. That is an estimate of the projectile, not the crater’s diameter. It does not establish the object’s composition, original orbit or precise impact speed.
The Lunar and Planetary Institute reports a crater diameter of 222 meters and an average depth of about 43 meters. It lies near a transition between rugged highland terrain and a smoother lunar mare. Bright material extends outward from the rim: this ejecta is rock and dust excavated and redistributed during the collision.
Researchers estimate that a crater of this size forms somewhere on the Moon roughly once every 130 years. This is an average inferred from crater-production models, not a timetable. It does not mean the Moon is protected from another comparable impact until a century has passed, nor does it imply smaller impacts are rare.
McGetchin is exceptional among newly formed craters documented during LRO’s mission. Calling it “massive” is reasonable in that observational context, but it should not be confused with the Moon’s ancient giant basins. The discovery concerns a fresh, measurable change, not the largest crater the Moon has ever experienced.
Why did a new crater appear on an apparently unchanging Moon?
The Moon’s familiar appearance hides an active history of bombardment. NASA’s Moon Facts explains that its extremely tenuous exosphere does not provide meaningful protection against incoming meteoroids. There is no thick atmospheric shield comparable to Earth’s to slow or destroy many smaller objects before they reach the ground.
Over billions of years, impacts have fragmented the lunar surface into boulders, smaller rocks and fine dust. This loose material is called regolith. The pale highlands and darker maria record different geological histories, and the craters preserved within them provide evidence of bombardment across the inner solar system. A new impact adds another layer to that record.
What makes McGetchin valuable is its youth. An ancient crater has accumulated later impacts and other surface changes, making its earliest condition difficult to reconstruct. A recently formed feature gives researchers a much clearer starting point for studying freshly excavated material and the surrounding disturbance. Its known formation interval helps separate initial effects from later alteration.
Image: NASA Goddard/Intuitive Machines/Robert Wagner. Wide-Angle Camera comparison; the bright new spot is ejecta. The displayed image dates are broader reference views, not the endpoints defining the 2024 impact window.
LRO makes these comparisons possible because it has studied the Moon since 2009. Its mission measures surface shape, composition, temperature and radiation, producing information useful both for science and for choosing exploration sites. Repeated coverage matters: a single photograph reveals a feature, while observations separated in time can establish that something changed.
NASA reports that image-processing specialist Robert Wagner noticed McGetchin’s unusual debris pattern during a map-quality check on October 24, 2025. Sharper follow-up camera images then revealed its form. The dates of formation, recognition and publication therefore describe different stages of the investigation; treating all three as the date of the impact would distort the finding.
Why is the surrounding ground colder at night?
Visible images show where material moved, but temperature measurements reveal changes that are less obvious to the eye. UCLA reports that LRO’s Diviner instrument found an approximately 7-kilometer-wide nighttime cold spot around McGetchin. That affected region extends far beyond the 222-meter crater, showing that the physical consequences cannot be judged from the rim alone.
The explanation involves disturbed regolith. The impact churned and loosened surrounding material, changing how effectively it retains heat. At night, this altered surface becomes colder than nearby undisturbed ground. The false-color thermal maps visualize temperature differences; blue is a plotting choice, not the visible color of the lunar soil.
A cold spot is not evidence that the collision created a lake of ice, and it does not mean the entire Moon cooled. It is a localized thermal response of the ground. Comparing measurements before and after the event helps connect that response with the fresh impact rather than merely identifying a naturally cold region.
Image: NASA Goddard/UCLA/JHU APL. Diviner thermal-map frames with explanatory labels added. Original scale bars and temperature keys are preserved.
For researchers, a young crater is also a calibration opportunity. Following the site can help show how newly disturbed ground evolves. For exploration, the wider lesson is that a surface may have altered physical properties well beyond an obvious depression. Understanding those changes provides context for interpreting terrain and planning future work on the Moon.
Conclusion
McGetchin was caused by a natural collision in spring 2024, although the incoming object’s exact type remains uncertain. Its fresh ejecta and extensive nighttime cold spot make it a useful natural experiment. The discovery shows why long-running lunar observations matter: they reveal both the visible scars of impacts and subtler changes in the ground around them.
Sources & Further Reading
- NASA’s Moon Orbiter Spots New, ‘Once-in-Century’ Moon Crater
- NASA’s Lunar Reconnaissance Orbiter Discovers a New 222-m Diameter Lunar Crater
- Rare New Lunar Crater Shows How Impacts Remodel the Moon’s Surface
- A New Lunar Crater: McGetchin
- Moon Facts
- Lunar Reconnaissance Orbiter
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