The Grand Canyon in Arizona got carved by water over millions of years of slow but steady erosion. Two similarly-sized canyons on the moon got carved by flying rocks in about 10 minutes. That's because these two canyons formed in the wake of an asteroid or comet smashing into the moon,

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.

The Grand Canyon in Arizona is one of Earth's natural wonders, carved out over millions of years by the gradual erosion power of the Colorado River. Close to the moon's south pole are two canyons each comparable in size to the Grand Canyon that were born in a much different process.

Each year, millions of visitors marvel at the geological intricacy and beauty of the vast chasm of the Grand Canyon carved through the Arizona desert by 5 million years of water erosion. It is interesting to contemplate the force of water as over the eons the Colorado River meticulously sliced through layers of Arizona bedrock.

CAPE CANAVERAL, Fla. (AP) — 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 lunar far side.