Lunar Core

A new study using old data has concluded the Moon has a core similar to Earth. Using data from the seismic stations set up by Apollo astronauts, plus techniques used to study the interior structure of Earth, the study finds the Moon has an iron core surrounded by a molten shell, like Earth, but the Moon seems to have a ring of magma around that shell, too.

In short, the more we learn about the Moon, the more distinctive it becomes as a world in its own right, and the more potentially useful that world becomes as we expand into the Solar System.