This "13th sign", however, has been there for thousands of years. The Sun passes through it once a year as it travels from Scorpio to Sagittarius.
The constellation Ophiuchus may be based on Asclepius, the ancient Greek God of Medicine (in Latin he was called Aesculapius). He learnt the art of healing from Chiron, the Centaur.
On either side of Ophiuchus in the heavens lie the two parts of the sign of the serpent he holds, Serpens Caput, the Serpent's Head and Serpens Cauda, the Serpent's Tail. It is from the Serpent that Ophiuchus learnt the secret of the Elixir of Life.The "rod of Asclepius" consisted of a serpent entwined around a staff. It has been used as a symbol of the medical profession ever since (although it has been confused with the caduceus in modern north America).
Asclepius was the son of Apollo and his mother Coronis. Coronis died before his birth, but Apollo surgically removed the baby carried it to the centaur Chiron who raised Asclepius and instructed him in the art of medicine. Among his children were his daughters Hygieia, Meditrina, and Panacea. The names of his daughters each rather transparently reflect a certain subset of the overall theme of "good health".
Zeus killed Asclepius with a thunderbolt because he raised Hippolytus from the dead and accepted gold for it. Other stories say that Asclepius was killed because after bringing people back from the dead, Hades thought that no more dead spirits would come to the underworld, so he asked his brother Zeus to remove him.
The even older Babylonian version of Ophiuchus, however, is slightly different. Here the serpent is Tiamat, the Monster of the Bitter Ocean. Holding Tiamat is Marduk, the Sun God of the Babylonians. They are doing battle together in the eternal fight of good against evil.
