Two Grand Canyon-size features on the far side of the moon were likely formed in about 10 minutes after an unknown object slammed into the moon 3.8 billion years ago.

New research shows that when an asteroid slammed into the moon billions of years ago, it carved out a pair of grand canyons on the far side.

Scientists proposed an explanation for the formation of Vallis Schrödinger and Vallis Planck near the lunar south pole, which are each about the size of Earth’s Grand Canyon.