Researchers have found a massive crater on the moon, larger than the Roman Colosseum, which resulted from a significant impact event two years ago that initially went unnoticed.
This steep crater measures about 728 feet in diameter and reaches depths of up to 141 feet, making it the largest known impact crater formed in fairly recent times in our solar system.
Such monumental events are thought to happen approximately once every 132 years, so this discovery could provide a wealth of information, particularly as NASA gears up for its plans to establish a lunar base for astronauts.
Describing this occurrence, scientists noted, “This event constitutes a statistically rare, effectively once-in-a-lifetime observation,” in one of the two studies published in the journal Science Advances.
The Lunar Reconnaissance Orbiter (LRO) spotted the crater on the moon’s near side in May 2024, shortly after it was created by a fragment from an asteroid or comet.
Interestingly, the event went undetected by telescopes on Earth and in space in real-time.
The LRO’s wide-angle images were only recognized amidst the overwhelming amount of data in August 2025.
Subsequent detailed images were taken last fall, leading to confirmation of the discovery earlier this year.
This crater, named after the late Thomas McGetchin, who previously directed Houston’s Lunar and Planetary Institute, is three times larger than the previous record-holder found by the LRO a decade ago.
The moon, which has been pockmarked for countless ages, contains some of the solar system’s largest impact craters, one of which spans over 1,500 miles.
This recent impact disturbed the lunar surface over an area exceeding 66 miles.
According to Mark Robinson, chief scientist for the LRO cameras and one of the study’s lead authors, the dust and rocky debris were ejected at higher angles than expected.
A separate study also pointed out a four-mile-wide cold spot around the new crater, indicating a change in the moon’s upper layer due to the impact.
Co-author David Paige from UCLA compared the situation to gardening. He stated, “We’re now thinking of impacts as a way to garden the regolith — churning the sediments and putting stuff above that’s usually below the surface.”
Since its launch in 2009, the LRO has discovered numerous craters, revealing that the moon’s top inch of soil is being disturbed by ejected material every 80,000 years—a rate quicker than previously assumed, according to Robinson.
He also noted that contrary to popular belief, the Apollo moonwalkers’ dusty footprints will not last forever; they will “definitely be long gone in that time frame.”
The next step involves assessing the likelihood of debris from the crater impacting NASA’s planned lunar base, which will be essential for engineers to develop structures that can withstand potential damage, or at least reduce concerns.
