April 29, 2013
Draco, the Dragon, was an important constellations to the ancients. The ancient Egyptians even worshipped a single star within its environs. The star isn’t particularly bright, and these days, it isn’t even particularly well placed in the sky. Why was it so important?
I’ll answer that question later, but last week I promised another story about the constellation, so here goes:
The ancient Greeks associated Draco with the giant dragon Ladon, one of the extremely nasty household pets of Hera, queen of the gods. Ladon’s job was to guard the golden apples that grew on a tree planted in Hera’s garden on the slopes of Mount Atlas. Three beautiful sisters, called the Hesperides, were originally assigned the job of guarding the apples, but they couldn’t resist picking them. So Hera added Draco, who coiled himself around the tree. And a worthy guard he was. He had 100 heads, each of which was deadly.
Along came Hercules (yes, him again), the greatest of the Greek heroes, who was assigned the job of stealing the apples as one of his 12 labors.
He slew the dragon with poison-tipped arrows, and made off with the apples. The next day, a group of famous Greek adventurers called the Argonauts came upon the scene.
The sight they saw was worthy of any of the sleazy horror epics so popular these days. Nearby, the Hesperides wailed over the corpse of the dragon. Dead flies covered Draco’s body. They soon died an agonizing death themselves from trying to drink the dragon’s poisoned blood. Draco was even nastier in death than he was in life.
Hera loved her pet. Anyway. To honor his memory, she put him among the stars, where he is to this day.
Not all cultures saw the constellation as an evil beast. To the ancient Chinese, it was an ultimately important locale — dwelling place of the ruler of the sky. It was called Tsi Kung, the “Palace of the Heavenly Emperor.” At the curve of the dragon’s tail was Tien Choo, or Heaven’s Kitchen. The stars of the tail behind it were various governmental ministers and palace servants, including stewards and even the palace governess.
Why have we lost track of Draco when the almost equally faint Little Dipper is so familiar to us? Most people know the Dipper because it contains a single star called Polaris. Polaris is now the pole star, the star that happens to be almost straight north.
As a result, it seems to stand still while the other stars circle slowly around it.
Because the earth wobbles a little on its axis as it rotates, the pole star changes over the millennia. Five thousand years ago, the faint star Thuban in Draco’s tail, and not Polaris, was almost directly north. Draco was thus the most important constellation in the sky.
To the Egyptians, Thuban was the place where their dead Pharaoh entered the heavenly realm and joined his compatriot gods. To others, Thuban was the nail that held up the heavens, the single unchanging point in an ever-changing cosmos.
Saturn is visible as that bright, yellowish “star” in the SSW just after dark. Look for it to the far right of the very bright star Spica in the constellation Virgo. Saturn is still just below and to the left the fainter star Porrima, also in Virgo. The two will appear in the same binocular field and even, including the rings, in a low-to-medium-power telescope field.
Just before morning twilight, start looking for the three bright planets in the east, but look soon. What was a triple conjunction will soon become a double.
Bright Jupiter is getting high in the east. Look in binoculars for the planet’s four brightest moons. They often set themselves up in a perfect line around the planet. You’ll need a small telescope to see Jupiter’s cloud bands stretches horizontally around the planet.
Below and to the left is fainter Mars, a red speck. Binoculars will help you to see it as a slightly brighter red speck.
Venus is diving toward the sun, but it is also the brightest of the three. You might begin to see it after morning twilight as Jupiter fades and Mars disappears.
Tom Burns is the director of Ohio Wesleyan University’s Perkins Observatory. firstname.lastname@example.org