Scientists found that two giant canyons close to the Moon’s south pole, named Vallis Schrödinger and Vallis Planck, were created in just minutes when a meteor, 15 miles wide, struck the Moon 3.8 billion years ago. These canyons are unlike the Grand Canyon, which was created by the erosive power of rivers over millions of years, but in these cases, it was an instantaneous creation.
The impact carved out a 200-mile-wide crater and hurled huge rock pieces into space. The fragments entered the Moon at such extreme speeds that they formed deep, straight canyons over 165 miles long, which plunge over 1.5 miles into the lunar crust. Dr. David Kring of the Lunar and Planetary Institute in Houston explained the sheer magnitude of this event, stating that the energy released was over 130 times the explosive power of all nuclear weapons on Earth today.
Using NASA’s Lunar Reconnaissance Orbiter image, Dr. Kring and his colleagues, Danielle Kallenborn and Gareth Collins of Imperial College London worked out a model of what happened to rebuild the canyons. The impact threw giant rock fragments at a speed greater than 2,000 miles per hour, which, in rapid succession, hit the Moon’s surface and caused craters as wide as 20 kilometers in diameter across the canyons in the form of a chain of explosions.
One of the most interesting findings was that the canyons did not seem to originate from the very center of the Schrödinger basin crater. Instead, their orientation seemed to indicate that the meteor struck at an angle, hitting a little south of the crater’s center. As reported by Dr. Jennifer Anderson, a geoscientist at Winona State University, the discovery means crater rays point back to an impact site that is “up range” from the center of the crater, meaning the asteroid likely came from the south.
This discovery has significant implications for NASA’s Artemis mission, which plans to put astronauts near the Moon’s south pole. Researchers now believe that the previously chosen landing sites are not disturbed by debris from the Schrödinger impact and thus are prime locations to study much older lunar rocks deposited in the South Pole–Aitken basin, one of the Moon’s most ancient craters.
Despite the advances in understanding these canyons, scientists are still unsure why the ejected rock formed long, narrow rays instead of a uniform pattern. Some believe that pre-existing craters or uneven terrain may have influenced the debris distribution, but the exact cause remains unknown. Dr. Anderson, who observed similar patterns in lab experiments, admitted, “Nature is messy.”
