The Moon (月) is the Earth's only known natural satellite and is in a synchronous rotation approximately 384,403 kilometers from it. Hence, it always faces the Earth with the same one side while orbiting it. It is apparently uninhabited by any forms of life and is currently the only celestial object that has been physically visited by Man.
In the Sailor Moon series, the Moon was the home of the Silver Millennium in ancient times, which was ruled by the Moon matriarchy and the power of the Sailor Crystal associated with the Moon, the Silver Crystal.
The Moon Castle was located on the shores of the Mare Serenitatis (Sea of Serenity), and was the palace of the Moon matriarchy. It was destroyed when the forces of the Dark Kingdom, led by Queen Beryl, attacked, but in the manga and Sailor Moon Crystal, it was recreated by Sailor Moon after the death of Queen Metalia.
In Greek mythology, the goddess of the Moon was named Selene, the daughter of the Titans Hyperion and Theia and the sister of Helios, the sun god, and Eos, the goddess of the dawn. According to myth, one day Selene saw a man named Endymion on the Earth below and fell in love with him, and caused him to fall into an eternal sleep so that she could admire his beauty forever.
In Roman mythology, the goddess of the Moon was Luna or Diana.
- In Japanese calendar, Monday is called "getsuyoubi" (月曜日), meaning "the day of the Moon."