More Moon and Jupiter

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One of the odd things about the night sky is that the brightest objects of all don't actually produce any light of their own. All those little twinkling points of light are suns -- and many of them are brighter than our own. But the Moon and the planets Venus and Jupiter shine by reflecting light from the Sun.

Jupiter and the Moon keep close company late tonight. They're in the southeast at first light, with Jupiter a little above the Moon. It looks like a brilliant star.

Right now, Jupiter's about twice as bright as the brightest true star in the night sky. It looks so bright for a couple of reasons. First, it's the largest planet in the solar system. And second, it's blanketed by clouds, which reflect about half of the sunlight that strikes them.

The clouds form bands in shades of yellow, tan, and similar colors. Their light blends together to give the planet an overall creamy color.

The Moon looks brighter than anything else in the night sky, but it's actually quite dark. Its surface is made of volcanic rock and a powdery gray soil. Overall, they reflect only about a tenth of the sunlight that hits the Moon.

But the Moon is our closest astronomical neighbor, at a distance of a quarter-million miles, so it forms a big disk in the sky. Against the dark night, the Moon's brighter areas look white, with the dark areas taking on a blue-gray tint. But it's all just a reflection -- from a world that creates no light of its own.

Script by Damond Benningfield, Copyright 2008

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