Scorpius and Orion: the hunter and his eternal celestial foe
Why Orion sets as Scorpius rises: the myth of the giant hunter, the red star Antares and the claws that became Libra in the ancient sky.
In the night sky two figures never meet. When Scorpius, with red Antares, rises in the south-east on summer evenings, Orion has already disappeared below the horizon; when Orion dominates the winter sky, Scorpius remains hidden. The ancients watched this alternation closely and read into it a story of boasting, divine revenge and endless flight.
The giant hunter
Orion was, according to myth, a giant of extraordinary beauty, son of Poseidon in many versions, able to walk on the waves. His adventures are told in very different ways. On Chios he was blinded by King Oenopion, whose daughter he had pursued; he regained his sight by walking eastwards, guided by little Cedalion, whom he carried on his shoulders, until the rays of the rising Sun healed his eyes.
Homer, in the Odyssey, shows him in Hades still chasing the beasts he had killed in life, with a club of bronze. It was precisely his passion for hunting, according to one of the best-known versions, that led to his death: Orion boasted that he could kill every animal on earth. The Earth, offended by such arrogance, made a scorpion rise from the ground, which stung and killed him.
Death and catasterism
Other versions attribute the sending of the scorpion to Artemis or to Leto, whom Orion had offended; others still have the hunter die by an arrow of Artemis herself, tricked by her brother Apollo. In every case both protagonists were placed in the sky, but far apart: tradition holds that the gods wished to keep them separate, so that one always sets when the other rises. Aratus, in the Phaenomena, already describes Orion fleeing towards the edge of the sky as soon as Scorpius rises in the east.
The constellation of Scorpius is among the oldest in the zodiac. The Babylonians already knew it as a scorpion, and in the Epic of Gilgamesh there appear the scorpion-men, guardians of the mountains where the Sun rises. Originally the Greek figure was larger: its claws extended into the region that the Romans later turned into a separate constellation, Libra, whose older Greek name was precisely Chelai, “the claws”.
Antares and the stars of Orion
The heart of Scorpius is Antares, a red supergiant. Its name means in Greek “rival of Ares”, because its colour recalls that of the planet Mars, which sometimes passes close to it. Orion, on the other side of the sky, is perhaps the most recognisable constellation: the three aligned stars of the belt, red Betelgeuse on the shoulder and blue Rigel at the foot form a pattern that almost every culture has noticed.
The celestial pair tells a lesson the ancients loved to repeat: strength and beauty offer no shelter from excess, and even the greatest of hunters can be brought down by the smallest of animals. Every year the cycle of the seasons stages their chase again, with Orion fleeing westwards just as his ancient adversary returns to rise.