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Venus and Mercury

April 5, 2010

The evening sky serves up a rare treat the next couple of weeks: a chance to see the elusive planet Mercury. That's because it has a brilliant companion: Venus, the "evening star." They're low in the west as the Sun goes down, and pop into view over the following half hour or so. Mercury is to the lower right of Venus.

Mercury is actually one of our closest planetary neighbors. At the moment, in fact, it's closer to us than any other planet.

Even so, Mercury is usually hard to find. One reason is that it's the smallest planet in the solar system. Another is that its surface is quite dark, so it reflects only about 10 percent of the sunlight that strikes it.

But the main reason is that Mercury is the closest planet to the Sun, so it never moves very far from the Sun as seen from Earth. As a result, the planet is visible for only an hour or two after sunset or before sunrise.

Even then, it's low in the sky, and often immersed in the glow of twilight, so it's hard to find. And even when you can see it, there's not much to make it stand out, so it's hard to know which star-like point of light is Mercury.

That's not a problem right now, though. Venus is by far the brightest of those points, so it really stands out. And Mercury is just a few degrees to its right or lower right. Mercury will remain beside Venus for several nights before it begins to drop back toward the Sun, and is once again lost in the Sun's glare.

Script by Damond Benningfield, Copyright 2010

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