The Zodiac --- The Constellation of Libra the Scales

Once part of Scorpius, then part of Virgo, Libra is a latecomer to the Zodiac. Note the position of the Scorpion's claw overlying the base of the Scale.

Libra The Scales is the seventh constellation of the Zodiac. Astronomically the sun is in Libra from the 31st of October to the 22nd of November. Libra is a dim constellation with no first magnitude stars. Zubenelchamali is its brightest star (at the Second Magnitude) followed by Zubenelgenubi, which is remarkable for being the only green star we can see with the naked eye. 

There's no evidence that Paleolithic Man knew Libra as a constellation separate from Scorpius, for Libra was considered to be just the claws of the Scorpion in time immemorial. The names of Libra's stars reflect this: Zubenelgenubi means "Southern Claw" and Zubenelchamali means "Northern Claw." 

Libra was known to the Babylonians, the last major Mesopotamian culture. Libra may have been invented due to a linguistic trick, for "Zubana" means "Claw" while "Zibanu" means "Balance." Since the Autumnal Equinox (the fall day when night and day are equal) occurs at the ancient First Point of Libra, it's most likely that the constellation was invented to mark out that astronomical moment. 

It's most likely that the constellation Ophiuchus was originally a member of the early Sumerian Zodiac. Ophiuchus lies athwart the ecliptic but today has been excluded from the Zodiac. Yet, in early Sumer, The Snake Handler would have been seen as a priest or god figure holding a serpent (or two) symbolic of Enki the wise god. The sun enters Ophiuchus between Scorpius and Sagittarius.

Having invented Libra, the fussy Babylonians exiled Ophiuchus from the Circle of Animals in the interest of keeping their astrological Zodiac neatly divided into 12 (13 may even then have been seen as unlucky). Also, the Babylonians revered Enki far less than Shamash their sun god, who was also the dispenser of justice. 

Libra's glyph, representing the scales.

Still, Libra struggled to assert itself. The late Egyptians saw Libra as a dhow, a type of Middle Eastern sailboat. Although the Greeks and the Romans counted Libra as "The Scales" and as a Zodiacal constellation, there is precious little mythology behind it. Until the eleventh century C.E. Libra was sometimes considered the Scales of Justice held in the hand of Virgo as Themis, the Greek goddess of justice. Up to 1851, one of its stars was still designated Gamma Scorpii. Libra, too, is the only member of the Zodiac that is an inorganic object. 

Later Mesopotamian astrologers, having invented Libra, postulated that the astrological "Libran Age" marked the Golden Age for humanity. This Golden Age took place approximately 17,000 to 20,000 years ago, and was reputedly a time when Man lived in harmony with nature; however, we now know that the Pleistocene Mass Extinction was occurring during this period, brought about by early man --- at the same time, this does not preclude an advanced civilization existing somewhere on Earth at the time, a civilization of which we retain only the dimmest recall.

Libra is the home of the globular cluster NGC 5897. 










Libra is also home to the Earth-like, potentially life-bearing, planet Gliese 581c .