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Planetary Flashes

February 7, 2012

Few sights in nature are more impressive than a lightning bolt — a discharge of electricity that's as hot as the surface of the Sun. And it's a common sight throughout the solar system. Lightning bolts that are far more powerful than those here on Earth light up the turbulent skies of Jupiter and Saturn, and lightning is as common on Venus as it is on Earth.

A spacecraft that's been orbiting Venus since 2006 has detected the "crackle" of lightning in radio waves coming from high in the planet's atmosphere. Mission scientists say the observations indicate that lightning flashes are as common on Venus as they are on Earth — an average of about a hundred per second.

There are some differences, though.

On Earth, lightning-producing clouds are made of water. But on Venus, they're made of sulfuric acid. And while the bottoms of the clouds on Earth are as little as a few hundred feet above the ground, the clouds on Venus bottom out at altitudes of about 35 miles. So there probably aren't any bolts shooting from the clouds down to the ground. In fact, the clouds are so high up that, from the ground, many of the lightning flashes would be invisible — lost in the haze of Venus's thick atmosphere.

Venus is high in the southwest as night falls this month. It's the brilliant "evening star," so you just can't miss it. And right now it's closing in on a much fainter world; we'll have more about that tomorrow.


Script by Damond Benningfield, Copyright 2011


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