NASA orbiter discovers 222-meter McGetchin crater formed by 2024 lunar asteroid impact

Discovery of McGetchin crater

Scientists analyzing images from NASA's Lunar Reconnaissance Orbiter (LRO) have discovered a fresh impact crater measuring 222 meters wide and 43 meters deep on the eastern limb of the Moon. Named McGetchin after American geologist and lunar researcher Thomas McGetchin, the crater formed between 11 April and 22 May 2024 following the collision of an asteroid or comet estimated to be the size of a three- to six-story building (at least 9 meters across). The impact went unobserved by Earth-based and space telescopes for two years until image processing specialist Robert Wagner noticed an unusual feature while reviewing composite lunar surface maps.

Wagner, who works with the Lunar Reconnaissance Orbiter Camera team and aerospace company Intuitive Machines, identified a distinct bright spot encircled by a dark halo that was absent from earlier orbital scans. He immediately paused his routine review to inspect the anomaly across sequential imagery.

I simply stopped, dropped everything, and began investigating what that spot was.

Physical scale and thermal effects

The discovery, detailed in two papers published in the journal Science Advances, represents the largest newly formed impact crater identified in the solar system in modern observation. Statistical models cited by the researchers indicate that collisions of this magnitude occur on the Moon roughly once every 132 years. McGetchin is three times the diameter of the previous record holder discovered by the orbiter ten years ago, spanning an area wider than two 105-meter football pitches and exceeding the footprint of the Roman Colosseum.

The collision displaced lunar regolith across a radius exceeding 100 kilometers. Mark Robinson, principal investigator for the orbiter camera system and lead author of one of the studies, reported that ejecta and rock fragments were propelled at steeper angles than standard cratering models anticipated. Measurements from the spacecraft's Diviner thermal instrument revealed a cold zone extending across a radius of roughly 6.5 kilometers around the crater. Nighttime temperatures within this zone are approximately 9 degrees Celsius colder than surrounding terrain, caused by loosened, low-density debris that retains less solar heat.

Seventeen years of orbiter observations

Because the Moon lacks a protective atmosphere, incoming space rocks strike its surface without deceleration or ablation. Small fragments the size of car tires generate craters roughly 10 meters wide at a rate of approximately 140 per year, though many smaller events remain below detection limits. Over 17 years in lunar orbit since launching in 2009, the NASA probe has cataloged more than 1,000 new impact craters and tracked over 100,000 distinct surface variations through automated and manual image comparisons.

This event constitutes a statistically rare, effectively once-in-a-lifetime observation.

Implications for future lunar exploration

While the Moon contains ancient formations far larger, such as the 2,500-kilometer South Pole-Aitken basin, McGetchin provides researchers with an opportunity to observe freshly altered geology in pristine condition. Analyzing ejecta distribution and weakened surface regolith aids mission planning for upcoming crewed lunar surface exploration. NASA is preparing for an astronaut landing under the Artemis program in 2028, its first crewed descent since Apollo 17 in 1972, while China has scheduled a crewed lunar landing for 2030. The altered physical and thermal conditions around new craters will inform rover mobility engineering and landing zone selection.