WASHINGTON, Sept. 27 (UPI) -- Weather on Venus with 800-degree temperatures and sulfuric acid clouds is often described as unchanging and boring, but U.S. astronomers say that's not so.
While it might be true at the planet's surface, where the atmospheric pressure is a crushing 90 times that of Earth's, a new analysis of data by NASA and international scientists suggests that higher up things get more interesting, a NASA release said Tuesday.
"Any variability in the weather on Venus is noteworthy, because the planet has so many features to keep atmospheric conditions the same," Tim Livengood of the University of Maryland said.
"Earth has seasons because its rotation axis is tilted by about 23 degrees, which changes the intensity of sunlight and the length of the day in each hemisphere throughout the year," he said.
"However, Venus has been tilted so much, it's almost completely upside down, leaving it with a net tilt of less than 3 degrees from the sun, so the seasonal effect is negligible."
Still, variable weather does exist, researchers said.
Telescopic observations of Venus at about 68 miles above the planet's surface in cold, clear air atmosphere layers called the mesosphere and the thermosphere, showed the planet does, in fact, have interesting weather.
"The mesosphere and thermosphere of Venus are dynamically active," Guido Sonnabend of the University of Cologne in Germany said. "Wind patterns resulting from solar heating and east to west zonal winds compete, possibly resulting in altered local temperatures and their variability over time."
Venus, although almost Earth's twin in size, ended up with an extreme climate, and astronomers say a deeper understanding of its atmosphere will let researchers compare it with the evolution of Earth's atmosphere, perhaps revealing why Earth now teems with life while Venus suffered a hellish fate.
