Libra is the seventh sign of the zodiac. It spans 180 ° – 210 ° longitude. Under the tropical ecliptic, the sun transits between September 23rd and October 23rd (North autumnal equinox) on average, while under the stellar ecliptic, the sun currently passes through Libra from about October 16th to November 17th. Based on the justice scale of Themis, the personification of Greek divine laws and customs. She became the inspiration of the modern description of the goddess of justice. Libra's ruling planet is Venus, but some may also see iris as its ruler. Libra is the only constellation in the sky represented by inanimate objects. In the whole process of history, the other eleven symbols are expressed as animals or mythical figures.

Libra is one of the three constellations. The others are Gemini and Aquarius. The sign of Libra is indicated by the scale. According to the Romans of the first century, Libra is an overthrow. When Rome was founded, it was said that the moon was in Libra. Under this symbol of justice, everything is in balance. The Roman writer manilius once said that Libra is "the sign of four seasons balance". The time of day and night match each other. So why did Romans trust the "balance sign" so much. Back in ancient Greece, the constellation between Libra and Scorpio was once ruled by Scorpio. They call this area the Latin word "chelae," translated as "claws," which helps identify the individual stars that make up the entire constellation of Libra, because it's very close to the constellation Scorpio in the sky.