"The Scales"
Mythology: Originally, this constellation was part of the constellation of Scorpio. Around the first century B.C., this constellation became the Scales. The most agreed upon reason for this change is that the Sun is located in Libra during the autumnal equinox (the equinoxes being the only two days of the year when there are 12 hours of day and 12 hours of night). Because of this balance between night and day, many ancient cultures -- Romans, Egyptians, Indians, and Chinese -- referred to this space as the Balances. It is interesting to note that because of this change (from being a part of Scorpio), Libra is the only constellation on the zodiac that is not an animal or a person.
Interesting Trivia:
As time went on, Libra also became associated with the Scales of Justice.
In making this association, the constellation Virgo, to the west of Libra,
has become symbolic with Astraea or Dike -- the Goddess of Justice.
Astraea would judge the dead by weighing the aspects of their lives in
her balance.
One of the more unusually named
stars, Zubanelgenubi, has appeared in some research to appear a greenish
color. Astronomers and scientists are still questioning these findings,
and are also trying to determine the mechanisms that could make it true.