The constellation is Libra, the scales or balance, and as a present-day zodiac sign it rules from September 23 to October 22. One explanation of its name is that it rises at the time of the autumnal equinox, when the day and the night are of equal length, a balance being a device for determining equivalents. A more questionable interpretation is that it appeared at harvest time, when farmers were weighing their produce for marketing purposes.
But more likely it had another origin. In Akkadian — an ancient Semitic language spoken by, among others, the Assyrians — this constellation was called zibanitu, which means “the claws of the Scorpion,” because it rose before the constellation of the Scorpion and was thought to be the front part of it. But zibanitu could also mean a weighing scales — a scorpion held upside down is similar in shape to the ancient form of this device.
The constellation is now known only as Libra, a Latin word meaning “scales or balance.” It is usually pictured as — guess what — a scales or balance, consisting of a crossbar suspended from a central arm or chain, with a pan hanging from each end of the crossbar. It’s the only zodiac sign that isn’t an animal or a person, although it’s frequently held by a young woman, often identified as Astraea, the daughter of Zeus and Themis. Both Themis and Astraea were goddesses of justice, and Astraea is also known as the constellation Virgo, the virgin.
Thus, in the Virgo-Libra configuration, we see a young woman holding a double-armed scales and identified with Justice.