This is The dark side of the moon. It's remote and mysterious and not just because we can't see it from Earth.

When viewed from space, the moon's backside looks totally different from its front.

Now, researchers think they have a solution to the mystery, which they share in the

astrophysical journal letters.

You may have wondered about the man in the moon, that face-like image made by the large

flat plains on the lunar surface that faces us.

But scientists wonder why the far side doesn't have comparable features.

According to the new analysis, this asymmetry has to do with how the moon was made.

Not long after the Earth formed, a Mars-sized hunk of intergalactic debris

smacked into our baby planet, flinging off material that then became the moon.

The crash left both bodies boiling hot, but the

smaller moon cooled down more quickly than the molten earth, especially the part

that faced the other way. The minerals on the moon's cooler side started to precipitate sooner.

That head start gave the far side a thicker crust

which is more resistant to the weathering seen on the familiar side,

weathering that gives a face character even on the moon.

Thanks for the minute.

For Scientific Americans, 60 Second Science, I'm Karen Hopkins. I'm Karen Hopkins. it's no doubt sight in the moon really.