Sagittarius role, after the introspection of Scorpio is to take the hard won wisdom and create something worthwhile from it and spread it around.
A moon is defined as a natural satellite in orbit around another body that, in turn, is in orbit around its Star. The moon is kept in its position by both its own gravity, as well as its host's gravitational grip. Some planets have many moons, some have only a small number, and still others have none at all. Several asteroids inhabiting our Solar System are circled by very small moons, and some dwarf planets--such as Pluto--also host moons.
When the American astronomer James Christy discovered Pluto's largest moon Charon back in 1978, astronomers were quick to calculate the mass of the system. Pluto's mass was hundreds of times smaller than the mass originally estimated for it when it was first discovered in 1930. With Charon's discovery, astronomers suddenly acquired a new understanding that something was fundamentally different about Pluto.