More Moon and Venus
During the first half of the twentieth century, science-fiction writers filled the planet Venus with life. Venus is about the same size as Earth, it's closer to the Sun, and it's completely blanketed by clouds. So writers envisioned steamy jungles and giant oceans filled with life -- much of it mean and hungry.
In the 1960s, though, all that life simply vanished. When spacecraft flew past the planet, they found that surface temperatures are hundreds of degrees hotter than those on Earth. What's more, Venus's atmosphere consists mainly of carbon dioxide, and it's topped by clouds of sulfuric acid.
Even so, there's speculation that Venus could have been more Earth-like in the distant past. There's evidence that it once had a good bit of water. And with liquid water and plenty of solar energy, there's a chance that life could have taken hold.
A few years ago, two researchers proposed that life might still exist at Venus -- in a layer of clouds about 30 miles above the surface. Conditions are more tolerable there, and there's a smattering of water vapor. And the researchers found that the chemistry at that altitude is a little odd -- as if microbes were processing some of the chemicals to make new ones. So while Venus isn't a hotbed of life, there's a chance that it's not completely lifeless, either.
Venus is in good view this evening. It's the brilliant "evening star" below the Moon. It sets around four hours after the Sun.
Script by Damond Benningfield, Copyright 2008
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