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

In the afternoon, while his crew set up camp for the night, Powell would often climb into the canyon to investigate. Much has been learned about the geology of the Grand Canyon and about the ...

Two gigantic canyons on the moon — both deeper than the Grand Canyon — were carved in less than 10 minutes by floods of rocks ...