The Origins of the Moon

When we visited the earth first and we sampled it, people were surprised to discover that it's basically the same mixture of stuff as the earth. So that's why the moons made out of the same stuff the earth is made out of. And also once we understood something about the moons in our core, the moon has sort of a small iron core smaller than you would expect. The hypothesis is that a lot of that iron was probably lost from when the impactor hit the proto-earth and some of that was like melted and vaporized. This became a much more popular hypothesis after we went to the moon and visited and understood what it was made out of - there's a lot of really