Why is the far side of the Moon so heavily cratered?

The hemisphere of the moon that faces away from Earth is much more heavily cratered than the hemisphere we can see, but why is that?


Asked by: Colin Gray, by email

It’s often thought that the far side of the Moon is more exposed to incoming impacts, leaving it more battered than the side facing us.

In fact, calculations show both sides have been equally affected. The key difference is the far side has a much thicker crust. This thickness has prevented fresh, molten rock emerging from below to cover as many of its craters.

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