By Tom Burns
Last week, I told the tale of the constellation Corvus, the Crow, and Crater, the water cup of the god of Apollo, the ancient Greek god of wisdom and the arts.
Apollo had dispatched the Crow to fetch a cup of water. The Crow had other ideas. After it stopped to eat some fruit from a fig tree, it was very late in delivering the water.
As an alibi, the Crow grabbed Hydra, the Water Snake, and feebly claimed that Hydra had been guarding the water hole.
As punishment for its blatant lie, Apollo banished the bird to the nighttime sky with the Cup beside it.
Eventually, Hydra also joined the celestial tableau. That’s today’s story.
First, let’s find the constellations in question. Look low in the south around 9:30 p.m., just after the sky completely darkens. Corvus consists of four relatively bright stars forming a rough square. Crater is a faint semicircle of stars to the right of the Crow.
Hydra’s head is a small circle of stars just south of Cancer. Hydra’s thin, serpentine body stretches out as a long, meandering chain of stars to the southeast just underneath Crater and Corvus and for a considerable distance to the left and right of the two smaller constellations.
The ancients thus left us with a constellational confabulation of extreme weirdness, at least to our modern eyes. The Crow and Cup are riding the Water Snake across the sky.
To see how that happened, we must introduce a character familiar to most people even after more than two millennia.
Hercules is rising in the east. He is often at the center of such star stories, but he plays only a supporting role here.
The Lernaean Hydra was a gigantic, nine-headed sea monster raised by Hera, the queen of the gods. She loved her nasty little pet but had an ulterior motive for giving it such loving care.
She despised the hero Hercules because he was the son of her husband, Zeus, and a mortal woman named Alcmene, who was, shall we say, not Hera. She had been trying to kill poor Hercules even when he was a babe in his cradle.
So she raised the Hydra with one murderous goal in mind. Hercules.
The Hydra was well suited to the task. Each of its nine mouths had breath so bad that it killed anyone foolish enough to come too close. Its blood was a deadly poison. Its central head was immortal. As you might guess, the Hydra was not invited to many parties.
After its run-in with the Crow, Hydra apparently made its way back to its lair, a marshy region of the Peloponnesus in Greece called Lerna.
Here, Hercules reluctantly reentered the story. As the second of his 12 labors, he was commanded to slay the Lernaean Hydra — and with good reason.
Like all of Hera’s household pets, Hydra made life difficult for the locals.
Hydra’s swampy domain was well suited to a water snake. The region is relatively narrow, so travelers through the swamps had best beware lest they succumb to the poisonous breath of the beast.
Hercules ferreted out the Hydra and covered his face with a cloth to protect himself from the creature’s deadly exhalations. As he hacked away at its nine heads, he was chagrined to discover that three more heads would quickly grow in each of their places.
Hera loved her nasty little pet very dearly. So she sent the giant crab Cancer, also a constellational figure and another of her pets, to pinch him as he tried to kill the Hydra.
Hercules first had to kill the Crab and then solicit the aid of his charioteer to burn the bloody stumps with a torch as fast as he could cut off Hydra’s heads. Our hero then buried the immortal head under a boulder.
As Biff Smooter, my redoubtable observing buddy, might say, Hercules “wiped the snake guts off himself” and went on to his next labor.
The distraught Hera put Hydra in the heavens underneath the Crow and the Cup. She placed her beloved Crab nearby. There they sit to this day, a starry memorial to Hera’s terrible choice of household pets.
Tom Burns is the former director of the Perkins Observatory in Delaware.