A NASA scientist discovered the largest newly formed impact crater ever documented in the solar system, a 728-foot-wide crater on the Moon formed between April 11 and May 22, 2024, by a comet or asteroid impact. Named McGetchin after lunar scientist Tom McGetchin, the crater’s discovery during a routine data check highlights the Moon’s dynamic surface and the value of long-term orbital observation.
The impact, which occurred between April 11 and May 22, 2024, left a 728-foot-wide (222-meter) crater that spans two football fields and reaches 141 feet (43 meters) deep—deep enough to fit three yellow school buses stacked vertically.
The Discovery During a Routine Check
Robert Wagner, a scientist with NASA’s Lunar Reconnaissance Orbiter (LRO), stumbled on the crater during a routine data-quality check. I just stopped, dropped everything, and started looking into what that spot was,
Wagner said, describing how a bright patch surrounded by a dark halo caught his attention.
The crater, later named McGetchin in honor of pioneering lunar scientist Tom McGetchin, was identified through before-and-after images captured by the LRO. These images, taken years apart, revealed a dramatic transformation in the lunar surface. This event constitutes a statistically rare, effectively once-in-a-lifetime observation,
scientists wrote in a study published in Science Advances, per the Associated Press.
Impact and Surface Changes
The impact’s force threw dust and broken rock across more than 60 miles of the lunar surface. Researchers using the LRO’s thermal instrument, Diviner, found a 4-mile-wide area around the crater that is 16 degrees Fahrenheit cooler at night than its surroundings. This “cold spot” occurs because the impact fluffed up the regolith, making it less dense and less able to retain heat. The discovery underscores how impacts can alter the Moon’s surface far beyond the crater itself.
The crater’s location near the boundary between the Moon’s darker basalt-covered plains and brighter highlands offers unique opportunities for future missions. “Observations from the surface would be really valuable because they would allow us to correlate what we see and map from orbit with small-scale changes to surface texture, the distribution of ejected material, and other properties that can only be studied in detail from the surface,” said Tyler Powell, lead author of one of the studies, per Space.com.
Historical Context and Scientific Significance
The McGetchin crater is about three times wider than the previous record-holder for a newly formed crater identified by the LRO. Scientists estimate that an impact of this magnitude occurs on the Moon once every century or longer.
While the Moon’s lack of atmosphere allows space rocks to strike unimpeded, impacts of this scale are rare. The McGetchin crater’s size and clarity make it a critical case for studying impact processes, which could inform future lunar missions.
Legacy and Future Exploration
The crater’s naming honors Thomas McGetchin, a former director of Houston’s Lunar and Planetary Institute, whose legacy includes contributions to lunar science. A quote from McGetchin, published in a memorial, reflects the enduring impact of scientific work: “Shaping your stone means quietly doing your job as well as you can. Your identity will soon be lost to history but your stone, if well shaped and polished, will fit into the structure we call civilization and hold its weight as time sweeps past us and others build upon us.”
Future missions could use the McGetchin crater to study how impact processes differ across lunar terrain. This would improve our understanding of many aspects of the impact cratering process,
Powell said. The LRO’s ongoing observations continue to reveal the Moon’s dynamic nature, proving that even well-mapped celestial bodies still hold surprises.
While the McGetchin crater’s discovery is confirmed, questions remain about the exact size and composition of the impacting object. Researchers continue to analyze data from the LRO and other instruments. The crater’s unique location make it a prime target for future robotic or crewed missions, which could provide direct measurements of its properties. For now, the McGetchin crater stands as a testament to the Moon’s active geological history and the power of sustained scientific observation.