The document discusses the layers that make up the interior structure of the moon. It describes four main layers from the surface to the core: the regolith crust, the rigid mantle which is about 1,000 km thick, a non-rigid lower mantle that has been heated, and an inner core. The magnetic field of the moon is very weak, about one ten-millionth of Earth's field. The document also provides information about the number of moons orbiting different planets in our solar system and details on some of the larger and more unique moons.