Of this constellation too the initial traces date back to Babylonian and Egyptian times. It was introduced in the zodiac by the Greek Cleostratus of Tenedos in the late sixth century B.C. According to the myth, Kronos, husband of Rhea, to baffle her jealousy , changed into a horse and abducted the nymph Filira, daughter of Oceanus and Thetis. She borne him the centaur Chiron, who was immortal and meek. By divine gift, he was very learned and expert in medicine, and therefore became the beloved teacher of many gods and heroes.
During the fight against the Giants, Hercules accidentally let slip an arrow, which stuck in his master's knee, causing irreparable excruciating pain because Hercules' arrows had been dipped in the poisonous blood of the Hydra of Lerna.
In unbearable pain Chiron dragged himself to a cave, with neither hope of recovery nor of death. He therefore begged Zeus to revoke his immortality, and in exchange for his life asked him to let Prometheus free, who had been condemned to remain forever chained in the Tartarus. Shortly after the death of Chiron, to honor his wisdom and generosity, Zeus received him in heaven in the form of a constellation.
A different version of the myth says that Apollo, a son of Zeus', had been borne a son, Asclepius - the Roman Aesculapius, the god of medicine - by Koronis, daughter of the king of Thessaly. The young man, entrusted by his father to the centaur Chiron, learned medicine and also how to raise the dead (see the constellation of the Snake). Zeus was nevertheless frightened by the implications of that power, and stroke Asclepius dead with lightning. Apollo, to avenge his son's death, pierced the Cyclops - the makers of Zeus' thunderbolts - with an arrow of huge dimensions. Then he hid his arrow in the round temple dedicated to him at the center of the city of the Hyperboreans, mythical people located far north, where the wind Boreas blows. It was a prodigous arrow, which carried a Hyperborean on a journey around the world, providing him food to survive throughout the long trip. Afterwards the arrow flew up to the sky and became the constellation of Sagittarius.
Sagittarius is well below the celestial equator and therefore is not very visible at our latitudes. It occupies an area of 867 square degrees, and passes through the meridian at the end of August late in the evening. It borders the Snake, the Eagle and the Shield; in the east it borders the Capricorn and the Microscope, in the south the Telescope and the Corona Australis, and in west Scorpio and Ophiuchus.