LRO finds McGetchin, a 222-metre lunar crater formed in spring 2024

NASA's Lunar Reconnaissance Orbiter has mapped a new crater on the Moon's eastern limb that is 222 metres across and 43 metres deep. The feature is named McGetchin, after Thomas McGetchin, the geologist who directed the Lunar and Planetary Institute in Houston and died in 1979. Two papers in Science Advances, released in mid-September, date the impact to a window between 11 April and 22 May 2024.

Robert Wagner, who works with LRO camera data, found the crater on 24 October 2025 while running a routine quality check on a large mosaic. He stopped the other work, pulled older frames, and confirmed that a bright ejecta blot that had not been there in 2011 was now sitting on the eastern edge. "I just stopped, dropped everything, and started looking into what that spot was," he said in the NASA account of the find.

The object that made the hole was a fragment of asteroid or comet roughly the size of a three- to six-storey building. Wagner's team writes that crater-production models put an impact of this size on the Moon about once every 132 years. LRO has logged at least 1,000 new craters in more than 17 years of flight. None of the others approaches McGetchin. Tyler Powell, lead author on one of the papers, told Space.com the team was "extremely lucky it formed during the lifetime of the LRO mission" and that before-and-after coverage exists.

Diviner, LRO's thermal instrument, then found a temperature anomaly. A zone about four miles across, roughly seven kilometres, is about 16 degrees Fahrenheit, or 9 degrees Celsius, colder at night than the ground around it. David Paige of UCLA, a co-author, compared the effect to gardening: an impact churns regolith, lifts material that usually sits below the surface, and changes how the soil holds heat. The cold spot is not the crater. It is the disturbed blanket.

Wide-angle camera frames from summer 2025 show the ejecta as a white patch with a dark halo. Spring 2011 frames of the same 38-mile-wide scene do not. Diviner data from 15 November 2025 to 18 February 2026 filled in the thermal map after the visible-light discovery. The crater sits on the near side's eastern edge, which means future landers and the planned NASA base have a fresh, dated scar to study rather than a billion-year-old bowl.

Size helps fix the picture. Two hundred and twenty-two metres is wider than the floor of the Colosseum. Forty-three metres of depth is roughly three school-bus lengths stacked. Simple craters of this class have steep walls and little or no central peak. The Moon's well-known bowls, Tycho or Aristarchus, are tens of kilometres across and tens of millions of years old. McGetchin is small next to those and new next to everything else LRO has dated in flight.

The practical use is engineering. Crewed missions need a measured rate for rocks this size and a measured radius for disturbed soil. A 222-metre hole with a 7-kilometre cold collar is that measurement. Commercial landers that treat a patch of maria as a lease now have a dated example of what the surface can still do without warning. Wagner's group says more detail on the impactor's mass and speed will come in a later paper that uses the camera geometry already in hand.

McGetchin is the largest newly formed impact crater identified anywhere in the solar system. If the 132-year figure holds, the next one of this class will not fall in the working life of the present orbiter team. LRO happened to be flying when this one landed, and the archive happened to hold a clean 2011 frame of the same ground. That pairing is what turned a white spot on a mosaic into a dated event.