Moon and Company

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The three brightest objects in the night sky put on a gaudy display in the southwest after sunset the next few evenings. All you need to enjoy the show are a clear sky and a clear horizon.

The most prominent member of the group is the Moon. It's a thin crescent right now. That means that sunlight illuminates only a tiny sliver of the lunar hemisphere that faces our way -- the crescent.

It's nighttime across the rest of the lunar disk. But the night is quite brilliant, because there's an almost full Earth in the sky. Earth is much bigger than the Moon, and it reflects more sunlight back into space. The combination makes a full Earth more than 40 times brighter than a full Moon.

It's easy to see the effect. As twilight fades, you'll see that the dark portion of the lunar disk is bathed in a ghostly light -- the light of a brilliant Earth.

And speaking of brilliant, look to the right of the Moon for the planet Venus -- the brilliant "evening star" -- and to the upper left of the Moon for the not-quite-as brilliant planet Jupiter. They far outshine all the true stars in the night sky, so there's just no missing them.

Venus and the Moon are pretty low in the sky as darkness begins to fall, so you need a clear horizon to spot them. They drop from sight a couple of hours after sunset. Jupiter follows them a couple of hours later. The Moon will move closer to Jupiter the next couple of nights; we'll have more about that tomorrow.

Script by Damond Benningfield, Copyright 2008

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