Moon and Antares

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Mars continues to put on a good show as we head toward May. The planet stands high in the southwest as nightfall, and looks like a bright orange star.

As Mars drops toward the horizon after midnight, its celestial "rival" will be climbing into view in the southeast. It's especially easy to pick out the next couple of nights because it's near the Moon.

Antares is the "heart" of Scorpius, the scorpion. Its name means "rival of Ares;" Ares was the Greek name for Mars, the god of war. Like Mars, Antares shines bright orange.

The resemblance is only skin-deep, though. Mars is a planet -- a chunk of rock that's a bit more than half as big as Earth. Its orange color comes from rocks and soil on its surface that contain iron oxide -- rust.

Antares, on the other hand, is a true star. In fact, it's a true superstar -- one of the biggest, brightest stars in the galaxy. It's so big that if it took the Sun's place in our own solar system, it would swallow the four innermost planets -- including its rival, Mars.

Antares shines orange because its surface is thousands of degrees cooler than the Sun. Cooler stars look red or orange, while hotter ones are blue or white.

So there's really not much of a "rivalry" between Mars and Antares; the supergiant star wins hands down.

Look for Antares to the lower left of the Moon as they climb into good view around midnight tonight, and to the upper right of the Moon tomorrow night.

Script by Damond Benningfield, Copyright 2010

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