The Moon slides across the body of Taurus, the bull, tonight. It’s roughly half way between his face and shoulder.

Both features are outlined by star clusters. The face is outlined by the Hyades, which forms a “V.” The bright orange star Aldebaran represents the bull’s eye, at one point of the V. It’s not part of the cluster, though — it’s only about half as far away.

The shoulder is marked by the Pleiades — a sparkly collection of stars that looks like a small dipper.

The Hyades is the closest of all star clusters — just 150 light-years away. It consists of a few hundred stars. They’re packed together in a ball that’s about 65 light-years across.

The cluster actually contains more stars outside that zone. But they’re barely holding on. They’re being tugged by the gravity of some of the Milky Way’s giant clouds of gas and dust, as well as its spiral arms. In another hundred million years or so, most of the stars of the Hyades will have been pulled away, and the cluster will cease to exist.

The Hyades is about 625 million years old. The Pleiades, on the other hand, is just 115 million years old. It’s about three times farther than the Hyades, and about twice as massive — it contains at least a thousand stars. Yet it, too, is being pulled apart. As the Hyades fades away, so will the Pleiades — leaving the bull without his prominent face and shoulder.

More about the Moon and Taurus tomorrow.
 

Script by Damond Benningfield

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