Venus, Earth's scorched twin
A host of research from a European craft shows similarities, like lightning.
By ASSOCIATED PRESS
Published November 29, 2007
WASHINGTON - Nearby Venus is looking a bit more Earth-like with frequent bursts of lightning confirmed by a European spacecraft.
For nearly three decades, astronomers have said Venus probably had lightning - ever since a 1978 NASA probe showed signs of electrical activity in its atmosphere. But experts weren't sure because of signal interference.
Now the European Space Agency's Venus Express spacecraft, which has been orbiting the haze-shrouded planet for 20 months, indicates that the lightning was real.
"We consider this to be the first definitive evidence of abundant lighting on Venus," David Grinspoon of the Denver Museum of Nature and Science said Wednesday in Paris.
The finding is significant because lightning affects atmospheric chemistry, so scientists will have to take it into account as they try to understand the atmosphere and climate of Venus, he said.
Venus' weather forecasts had long thought to be "kind of boring ... steady winds for the next 400 years," said Allan Treiman, a senior scientist at the Lunar and Planetary Institute in Houston, who isn't affiliated with the research.
The lightning is cloud-to-cloud and about 35 miles above the surface, said University of California at Los Angeles geophysics professor C.T. Russell, lead author of a paper on the Venusian fireworks. It is being published in today's issue of the journal Nature as part of research released Wednesday presenting the first comprehensive findings from Venus Express.
The Venus Express spacecraft shows that Venus and Earth are not just sister planets but are nearly twins in important ways.
Not only are they comparable in size and mass, but they have similar amounts of carbon dioxide and once probably possessed nearly equal amounts of life-giving water.
But while Earth matured into the solar system's beauty queen, replete with forests, rivers and oceans, Venus, 30 percent closer to the sun, lost nearly all its water. Its clouds today are filled with sulfuric acid.
The reason? Location, location, location. "Venus is just too close to the sun," said Andrew Ingersoll, an astronomer at the California Institute of Technology, who wrote another research article in Nature.
Bursts of electrical energy from lightning are something that scientists have long theorized could provide the spark of life in primordial ooze.
But because of its unforgiving atmosphere, it's not likely on Venus.
"If life was ever something serious to talk about on Venus, it would be early in its history, not in its current state," said Sean Solomon of the Carnegie Institution of Washington, who was not part of the research team.
Information from the Los Angeles Times was used in this report.
[Last modified November 29, 2007, 02:25:55]
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