A meteorite carved two valleys as deep as the Grand Canyon on the Moon in just 10 minutes

A woman is expected to set foot on the Moon for the first time in history in two years. She will do so in the Aitken Basin at the lunar south pole, a region never explored by humans and which is one of the largest known impact craters in the entire solar system. Over 100 kilometers (62 miles) from the landing point, two valleys as deep as the Grand Canyon in the United States open up. Now, a study has revealed that these two gigantic cracks were formed in just 10 minutes after the impact of a meteorite 25 kilometers in diameter (15.5 miles) some 3.8 billion years ago.

“Several impacts on the Moon have created crater trails, but these two are the largest known,” David Kring, a researcher at the Lunar and Planetary Institute in the United States, told EL PAÍS. His team used detailed images from the satellite to generate maps that reconstruct the direction in which the debris trails were ejected after the impact, as well as their speed.

The impact of the meteorite, which could have been a rocky asteroid or a comet of ice and dust, created a large crater 320 kilometers (190 miles) wide. Much of the earth thrown up by the impact piled up at the rim, forming a circular mountain range with peaks reaching 2,500 meters (8,800 feet) in height. The impact also propelled curtains of rock beyond the crater, which fell like projectiles in a row. Each left holes about 20 kilometers (12 miles) wide.

The end result was two valleys: the Schrödinger valley and the Planck valley, which are about 270 kilometers (168 miles) long and up to three and a half kilometers (2.18 miles) deep. “They are as wide as the Grand Canyon and a bit deeper,” Kring sums up. His results were published on February 5 in the journal Nature Communications.

Researchers estimate that all of this happened in about 10 minutes. The energy released was about 130 times more powerful than the detonation of the entire world’s atomic arsenal, the study estimates. And the original impact that formed the crater was much more powerful, Kring notes.

The orientation of the two enormous valleys allows us to know that at the moment of impact, “the meteorite was moving away from the lunar south pole, which explains why the debris generated was thrown in that same direction,” explains the researcher. This space shrapnel was traveling at approximately one kilometer per second, about three times faster than the speed of sound.

When all this took place, Earth was under a bombardment of asteroids and comets equal to or even greater than the Moon. Impacts like the one in the Schrödinger crater also occurred on Earth, but their scars have faded due to erosion and plate tectonics. The study highlights that the Schrödinger crater basin is “the best available analogue” of the Chicxulub crater, formed by the meteorite that wiped out the dinosaurs some 66 million years ago, and which is now partly buried under the sea near the Yucatán Peninsula in Mexico.

Rocks 3.8 billion years old

The phenomenon studied is good news for the first astronauts who will reach the lunar south pole in the coming years. All the ground raised by the meteorite impact fell beyond the landing zone of NASA’s Artemis program. This will make it easier for astronauts to collect rocks that are more than 3.8 billion years old, corresponding to the earliest stage of the formation of the Moon and the Earth, the paper adds.

Jens Örmo, a researcher at the Centre for Astrobiology near Madrid and a specialist in simulating meteorite impacts, points out: “Not all meteorites form these types of impact canyons, and we don’t know why, it’s an enigma. This study is important to understand the distribution of the ejected rocks and the trajectory of the impacting body,” says the scientist, who was not involved in the study. The specialist compares the phenomenon to a canyon that spits out projectiles of different sizes. They all fly along a ballistic trajectory. The heaviest ones fall closer to the crater and the lightest ones much further away, but all in a line. The result of all this is very useful for humans, Örmo reiterates: “The impacts clear the first layer of soil and expose an older one, as if it were a natural drill.”

All of the geological features mentioned above will be invisible to the first astronauts to set foot on the Moon in 2027. At the lunar south pole, the Sun never rises completely above the horizon. The terrain casts long shadows and visibility is limited to a distance of about two and a half kilometres — half of what can be seen from a clear spot on Earth. The Schrödinger impact basin is about 125 kilometers (77 miles) from the Artemis 3 landing site.

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