  "Moon-magnetosphere interaction" stands for the interaction of magnetospheric
plasma with an orbiting moon. Observations and modeling of moon-magnetosphere
interaction is a highly interesting area of space physics because it helps to
better understand the basic physics of plasma flows in the universe and it
provides geophysical information about the interior of the moons.
Moon-magnetosphere interaction is caused by the flow of magnetospheric plasma
relative to the orbital motions of the moons. The relative velocity is usually
slower than the Alfv\'en velocity of the plasma around the moons. Thus the
interaction generally forms Alfv\'en wings instead of bow shocks in front of
the moons. The local interaction, i.e., the interaction within several moon
radii, is controlled by properties of the atmospheres, ionospheres, surfaces,
nearby dust-populations, the interiors of the moons as well as the properties
of the magnetospheric plasma around the moons. The far-field interaction, i.e.,
the interaction further away than a few moon radii, is dominated by the
magnetospheric plasma and the fields, but it still carries information about
the properties of the moons. In this chapter we review the basic physics of
moon-magnetosphere interaction. We also give a short tour through the solar
system highlighting the important findings at the major moons.
