New research finds an ancient asteroid strike carved out two grand canyons on the moon's far side

New research finds an ancient asteroid strike carved out two grand canyons on the moon's far side (Image: Reuters)

New research reveals that a massive asteroid impact billions of years ago created a pair of vast canyons on the far side of the Moon.

This discovery is promising for scientists and NASA, which plans to land astronauts at the south pole on the near side of the Moon. This region, unaffected by the asteroid impact, holds older rocks in their original state.

New research suggests that the canyons, located in the Schrödinger impact basin on the Moon’s far side, were carved out in less than 10 minutes by debris propelled into the air when an asteroid or comet struck the lunar surface approximately 3.8 billion years ago.

The impact released energy equivalent to 130 times the total global stockpile of nuclear weapons, according to geologist David Kring of the Lunar and Planetary Institute at the Universities Space Research Association in Houston, the study’s lead author. The findings were published in Nature Communications on Tuesday.

Scientists used data from NASA's Lunar Reconnaissance Orbiter spacecraft to map the canyons and applied computer modeling to analyze the flow directions and speed of the debris. They discovered that the rubble traveled at speeds of up to 2,200 miles (3,600 km) per hour.

One canyon, Vallis Planck, spans approximately 174 miles (280 km) in length and reaches a depth of 2.2 miles (3.5 km). The other, Vallis Schrödinger, is about 168 miles (270 km) long and 1.7 miles (2.7 km) deep.

The impact occurred during a period of heavy bombardment in the inner solar system, likely caused by a shift in the orbits of the giant planets—Jupiter, Saturn, Uranus, and Neptune. This change in their orbits is thought to have happened at that time.

The object that collided with the Moon is estimated to have been around 15 miles (25 km) in diameter, making it larger than the asteroid that struck Earth 66 million years ago, which led to the extinction of the dinosaurs.

Lead author David Kring of the Lunar and Planetary Institute in Houston described the event as "a very violent, a very dramatic geologic process."

"When the impacting asteroid or comet hit the lunar surface, it excavated a tremendous volume of rock that was launched into space above the lunar surface before it came crashing back down. Knots of rock within that curtain of debris hit the surface in a series of smaller impact events, effectively carving the canyons. Adjacent to the canyons, the debris would have covered the landscape," Kring said.

Kring noted that it is uncertain whether the two canyons are permanently shadowed, like some of the craters at the Moon’s south pole, adding, “That is something that we’re clearly going to be reexamining.”

The new discoveries are significant for future lunar exploration. The Schrödinger impact basin is situated near NASA's planned Artemis mission exploration zone, which aims to land astronauts on the Moon for the first time since the Apollo missions of the 1970s.

"Because debris from the Schrödinger impact was jettisoned away from the lunar south pole, ancient rocks in the polar region will be at or close to the surface, where Artemis astronauts will be able to collect them. Thus, it will be easier for astronauts to collect samples from the earliest epoch of lunar history," Kring said.

He further explained that these rocks would help scientists test theories about the Moon's origin, such as the idea that it formed when a large impactor collided with Earth, ejecting molten material into space, as well as the theory that the early lunar surface was a vast ocean of magma.