The ancient Greeks saw the Milky Way as the emblem of a tragic tale of betrayal and vengeance. As told by the constellational scholar Pseudo-Eratosthenes, the story reflects their almost-human failings raised to superhuman proportions.
Zeus, or Jupiter to the Romans, was the king of all the gods and was used to getting his way. He betrayed his wife, Hera, with a kind of offhanded but merciless zeal.
Hera reluctantly put up with his philandering. She couldn’t express her anger directly. Zeus was far more powerful than she.
At long last, she had a mortal baby to torment. Heracles was the illegitimate offspring of Zeus, king of the gods, and Alcmene, a human woman. His half-mortal, half-immortal parentage caused no end of trouble for the babe throughout his exceedingly difficult life.
For starters, Hera sent two monstrous serpents to kill the baby in its crib. But the babe was exceedingly strong. He reached out with his chubby, little hands and squeezed the life out of the slithering beasts.
Zeus knew that the baby was in mortal danger. Heracles must drink the mother’s milk of a goddess to achieve the immortality of a god. As you might imagine, Hera was unwilling to provide such a service to Zeus’s lust child. Zeus thus sent his messenger Hermes to lay Heracles beside her as she slept.
The infant did what came naturally and suckled the milk of immortality. Did I mention that the babe was strong? Hera awoke in pain and pushed the babe away. Her milk streamed across the sky as a glowing band of light we call the Milky Way to this very day.
None of those tales sound particularly “scientific” by our standards. However, other Greek myths hint at the more systematic explanations that would come later.
Some ancient writers suggested that the sun had, at some point, burned a scorch mark across the sky. The problem was that the Milky Way did not follow the same path across the sky as the sun.
Somehow, the sun must have strayed from its original path.
In a myth depicted in a play by Seneca and the writing of second-century-CE Greek Achilles Tatius, the Milky Way originated from adultery and cannibalism.
Atreus and Thyestes were brothers who competed for the throne of the Greek city of Mycenae.
Thyestes took the throne with some help from Zeus, the king of the gods. Atreus got Thyestes to agree to yield the throne if the sun rose in the west and set in the east, opposing its ordinary course.
Then Zeus got the sun god Helios to drive the chariot of the sun opposite to its regular course. Atreus ascended to the throne.
Soon thereafter, Atreus discovered that his spouse, Aerope, had an adulterous relationship with Thyestes. In a grotesquely vengeful act, Atreus cooked up Thyestes’ sons and served them to Thyestes at a banquet.
The sun god was so appalled by the scene that he turned away in horror. His motion caused the sun to be disturbed in its course to the one we observe today. The Milky Way is the imprint of the sun’s original path.
The ancient Greek story of Helios and Phaethon is the scorch-mark explanation that has survived most successfully in the modern world.
As told by first-century CE astrologer Manilius, the reign of the gods began with an apocalyptic war between the gods and the Titans, a race of supernatural creatures that preceded them.
When the gods triumphed, they gave some of their Titanic enemies onerous jobs. They burdened Helios with the rather sweaty task of dragging the sun across the sky in a horse-drawn chariot.
To Helios and the sea nymph Cymene was born the son Phaethon. His playmates did not believe that his father was the solar charioteer.
The boy insisted on driving the chariot for a day but could not control the mighty solar steeds. As the chariot careened around the sky, it sent the stars scattering in all directions. The Milky Way is the burn mark left by the sun or perhaps one of the dislodged stars.
Eventually sought more naturalistic explanations based on direct observation, as limited as those observations may be. More on that next week.
Tom Burns is the former director of the Perkins Observatory in Delaware.