Venus:
Holy Heat Wave!
A comedian on Venus could
make a career out of "it was so hot" jokes. But for planetary
scientists, intense heat on the second planet from the Sun is no laughing
matter. And there is no argument over global warming.
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Venus, as it might appear to an observer standing on the surface.
IMAGE: David Seal,
NASA/JPL/Caltech
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We're talking hot and
thick. Venus' atmosphere is nearly 100 times as dense as the one you breathe.
They call it a case of
runaway greenhouse effect, and some scientists say it might hold lessons for
where Earth's climate could be headed. The effect occurs because heavy doses of
carbon dioxide and other gases in Venus' atmosphere let the Sun shine in, but
then trap the heat like a black wool suit on a summer day in Atlanta. Earth's
atmosphere has less carbon dioxide; so while there is also a natural greenhouse
effect on our planet, it is more subdued. Much of the heat generated by the Sun
is re-radiated into space.
At least this is the basic
theory. But there's a puzzling aspect.
"Venus is much warmer
than one would predict based on the amount of sunlight it absorbs," said Andrew
Ingersoll, the Caltech planetary scientist. "Venus is closer to the Sun
and receives more sunlight than Earth, but it reflects a higher fraction, so it
actually absorbs slightly less than Earth," he said. Yet, "Venus is
much warmer than one would predict based on the amount of sunlight it
absorbs."
Okay, we bite. How hot
is it?
"The surface of Venus
is over 700 Kelvin while the surface of Earth is less than 300 Kelvin, on
average."
Translated -- That's 860
degrees Fahrenheit (427 degrees Celsius). Hot enough to melt lead.
Makes you wonder what SPF
to bring along.
Other news about weather in our solar system
Venus:
No Lightning, But a Strange Green Glow
Jupiter:
Cassini Snaps Earth-like Weather
Jupiter:
Cassini Makes First Color Movie of Clouds
Titan:
Earth-Like Weather and Methane Rain
The Sun: Space
Weather
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