The not so Quiet Moon - Blue Planet's Best Friend

The largest of the newly found graben, in highlands on the moon's far side.

Image courtesy ASU/SI/NASA

Images caught by NASA discovered some cracks on the Moon's surface. Scientists have always thought that the moon had no seismic activity, but nothing could be more wrong.

Actually, according to a new study, based on NASA images, the moon's surface wasn't at all quiet out there staring at Earth. In that lonely wilderness, the little Blue Planet's friend has been on a discrete activity, which surprisingly has stretched apart its surface forming shallow, sunken valleys, suggesting that the moon has undergone relatively recent tectonic activity, within the past 50 million years or so.

That activity in turn hints that the moon may not have been entirely melted, when it first formed roughly, 4.6 billion years ago. Instead, the early moon likely had a solid core covered by a global ocean of molten rock from here.

(Related: "Earth Had Two Moons, New Model Suggests.")