You are here

Moon and Pleiades

December 8, 2011

The parents of large families often feel like they’re carrying the weight of the world on their shoulders. But the father of a mythical group of sisters had reason to feel that way. He wound up bearing the weight of the entire Earth.

Atlas was one of the Titans — the gods who ruled before Zeus and the other gods of Olympus. His daughters were the Pleiads.

The whole family is represented in the stars, in the cluster known as the Pleiades. The dipper-shaped cluster is in the east at nightfall, a little to the upper left of the gibbous Moon. They stay close together all night long.

Although the Pleiades is also known as the Seven Sisters, the bright star at the end of the dipper’s handle is named for Atlas.

The star itself is several times as massive as the Sun. It’s also much hotter than the Sun, and radiates about a thousand times more energy into space. And because of its great heft, Atlas is already nearing the end of its life, even though it’s only about two percent as old as the Sun. Before long, it’ll puff up to much larger proportions, and shine many times brighter. After that, it’ll shed its outer layers, leaving only its hot but tiny core.

Despite Atlas’s powerful namesake, it’s not the most impressive star in the cluster. That title goes to one of the sisters, Alcyone, which is at the junction between the dipper’s handle and bowl — right where her overburdened father can keep an eye on her.


Script by Damond Benningfield, Copyright 2011


Get Premium Audio

Listen to today's episode of StarDate on the web the same day it airs in high-quality streaming audio without any extra ads or announcements. Choose a $8 one-month pass, or listen every day for a year for just $30.