The Sun enters Libra around the time of year when day and night are of equal length. Thus, this is when the Earth and the Sun are in balance...a time such balance is also illustrated by the fact that when the Sun reaches this point, Spring and Summer have passed and the harvesters are weighing and balancing the fruits of their labors. Now, the beginning of Autumn heralds the Harvest Season.
Under the tropical zodiac, the Sun enters Libra on the moment of autumnal equinox by definition on September 23, leaving it on October 23. Under the sidereal zodiac, it is currently there roughly around October 18 and November 16.
The origin of the word Libra derives from the Latin meaning "balances" or "scales." Often, a statue of the Goddess of Justice holding the scales or balances is erected over the domes of modern court houses. In ancient times, this constellation was associated with the judgment of the living and the dead. Libra is the only inanimate Sign of the Zodiac, the other eleven representing either human or animal forms.
Libra is home to the star Gliese 581, which has a planetary system consisting of at least 4 planets, including, Gliese 581 c, the first Earth-like extrasolar planet to be found within its parent star's habitable zone, Gliese 581 d, discovered in 2007 to be another Earth-like planet, and Gliese 581 e, the smallest mass exoplanet orbiting a normal star, both of which are of significance for establishing the likelihood of life outside of the Solar System.