Mercury in the Evening

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• 20 of 1968
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If you have binoculars, this is a good time to get them out. The planet Mercury puts in a brief appearance in the southwest not long after sunset for the next few evenings. It's quite low in the sky, though, so you need a clear horizon to spot it. And even though Mercury is fairly bright, it's immersed in the twilight, so the binoculars will help you pick it out.

We don't get to see Mercury very often because it's closer to the Sun than any other planet -- on average, a bit more than one-third of the distance between the Sun and Earth. As a result, Mercury always appears close to the Sun in our sky. At best, it's visible for a short while just after sunset or just before sunrise.

Mercury's proximity to the Sun would make it an unpleasant place to visit. Each square foot of Mercury receives about eight times more radiation from the Sun than Earth does. And Mercury has no atmosphere to protect it. Noontime temperatures at the equator soar to more than 800 degrees Fahrenheit.

Mercury also receives eight times more ultraviolet energy and X-rays than Earth does -- forms of energy that can be deadly. To walk on Mercury, you'd need heavy shielding. And if there was a big solar flare -- a giant explosion of particles and energy -- you'd want to stay under cover, well protected from the Sun's fury.

Look for Mercury in the southwest beginning a few minutes after sunset. The view is a little better from more southerly latitudes.

Script by Damond Benningfield, Copyright 2007

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