The Moon is unique in the solar system in its large relative size compared with the Earth. The Moon appears from the Earth to be the same size as the sun, in perfect artistic symmetry, unlike any known other planet-moon system. Moreover, unlike most planets in the solar system, Earth has only one moon, which is designed in two remarkable ways:

(1) it rotates and revolves such that only one side is ever visible to the Earth (the possibly only moon with this characteristic) and
(2) its side that faces the Earth is smooth, while the side that remains hidden is jagged. To those on Earth the Moon appears as an artistic disc that goes through phases of varying visibility from Earth.
