Earth used to have TWO moons... but one was destroyed in a giant solar collision

Earth used to have TWO moons... but one was destroyed in a giant solar collision | Mail Online: "Earth may once have had two moons - the one that shines at night today and a smaller companion, according to a new theory.

A slow-motion collision between the two is believed to have created the mountainous highlands on the moon's far side, as debris from the second, smaller moon piled up.

The side of the moon facing the Earth and the side facing away have strikingly different topographies. While the near side is relatively low and flat, the far side is high and mountainous with a much thicker crust."