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.

The extraordinary formations, each comparable in size to Earth’s Grand Canyon, are hidden on the far side of the moon — the side that always faces away from Earth — near the lunar south pole ...

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.

The extraordinary formations, each comparable in size to Earth’s Grand Canyon, are hidden on the far side of the moon — the side that always faces away from Earth — near the lunar south pole ...