Luna is the Latin word for moon, and the name is traditionally tied to nighttime illumination -- light that's borrowed and reflected rather than self-generated. It's often read as carrying a quieter, more contemplative kind of radiance than solar names, associated with cycles and gradual change rather than constant brightness.
Mercury conflicts with those who are ruled by Jupiter, and Jupiter conflicts with those ruled by Mercury. - Picatrix (Andalusia, ~1000.AD)