Jupiter (木星; Star of Wood) is the fifth planet from the Sun in this Solar System and the largest planet overall. It is the fourth brightest object in the sky (after the Sun, the Moon, and Venus). It has been known since prehistoric times as a bright "wandering star." It has also been notable for centuries for the so-called "big red spot" on its surface, actually a gigantic storm larger than the Earth. It has a large number of moons, but the four largest, and most well-known, are Io, Europa, Ganymede, and Callisto (now known as the Galilean moons). Astronomers believe that it plays an important protecting role in using its massive gravity to capture or expel from the solar system many comets and asteroids that would otherwise threaten Earth and the inner planets.
Jupiter, also known as Zeus in the Greek pantheon, was the king of the gods, the ruler of Olympus, and the patron of the Roman state. He was the son of Saturn, and the brother of Neptune, Pluto, Ceres, Vesta, and Juno (who was also his wife). His symbol was the thunderbolt and the eagle.
Jupiter is associated with moderation, kindness, and good fortune, and can represent a drive for growth and the pursuit of insight, understanding, and personal fulfillment. Jupiter is associated with Thursday, and the ruling planet of the sign Sagittarius, which is the same sign Makoto Kino was born under.
In Chinese astrology, Jupiter is ruled by the element wood. In Indian astrology, Jupiter is thought of as a great teacher.
- In the Japanese calendar, Thursday is called "mokuyobi" (木曜日), meaning "the day of wood."
- The name for Thursday in several Romance languages is derived from Jupiter's name (such as the French "jeudi" and Italian "giovedi").
- Nigel Henbest, The Planets, Penguin Books, London, 1992.