Moon and Spica

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You wouldn't want to get between a pair of stars that appear near the Moon early tomorrow. If their heat didn't get you, the X-rays and ultraviolet radiation would.

The stars are the main components of the system known as Spica. It's a little above or to the upper left of the Moon in the wee hours of tomorrow morning.

To our eyes alone, Spica looks like a single bright star. In fact, that's what it looks like through a telescope, too, because the stars are just 10 million miles apart -- about a tenth of the distance between Earth and the Sun.

Each star is impressive in its own right. Each is much bigger, heavier, hotter, and brighter than the Sun. And their mutual gravitational pull actually distorts the stars, so that each one bulges toward the other like a bright cosmic egg.

It would be an impressive system to see from up close -- but not too close. Because of their temperature, the stars produce copious amounts of ultraviolet radiation -- a type of energy that here on Earth causes sunburn and genetic mutations. Pass too close to these stars, though, and the radiation levels could be deadly.

The stars also produce "winds" of charged particles -- a hazard all on their own. But the winds from the two stars ram together and produce high levels of X-rays.

So perhaps it's just as well that we see Spica as a single point of light. Close enough to see them as individual stars might just be too close for comfort.

Script by Damond Benningfield, Copyright 2008

For more skywatching tips, astronomy news, and much more, read StarDate magazine.