Even though humans have pondered the moon since the first of us looked skyward, there is still much we don't know about it.

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

A giant impact 3.8 billion years ago sent a curtain of rock flying away from a point near the moon’s south pole. When that curtain fell, its rocks plunged up to 3.5 kilometers into the lunar ...