Hypnotic Cloud Movements on a Sister Planet
It’s mysterious. It looks alive. And, like so many other “mysteries” of the solar system, it has a name: the South Polar Vortex. Is this a place on Earth, like the so-called Oregon Vortex or the one that hooks tourists to seek out new age “wisdom” at Sedona, Arizona?
Nope. This one’s on Venus, and unlike the optical and “psychic” illusions hawked in the other two places, this one’s a real phenomenon. It’s a region in the polar atmosphere of Venus where atmospheric gases flow at different levels of the atmosphere. The undulating motion is a lot like what you might see if you pulled the plug on a bathtub full of water as the hot liquid gurgles down the pipes.
According to the folks at the European Space Agency, which runs the Venus Express mission currently studying our cloud-covered planetary neighbor, it’s not completely clear how the vortex formed and stays in place. Colin Wilson, at the University of Oxford, had a plausible suggestion grounded in every day atmospheric physics: “One explanation is that atmospheric gases heated by the Sun at the equator, rise and then move poleward,” he said. “In the polar regions, they converge and sink again. As the gases move towards the poles, they are deflected sideways because of the planet’s rotation.”
Wilson and others will keep a close eye on this vortex that is quite similar to other atmospheric vortices on Earth, including those observed at the centers of hurricanes. Nothing new-aged here, folks: it’s all good, solid planetary science!
Now, that’s just darned cool. The spacecraft “saw” something on either side of Rhea. This is very much like the first time Galileo Galilei “saw” something he took to be “ears” or “handles” on either side of Saturn as it appeared through his telescope in 1610. So, it’s kind of fitting that a modern-day descendent of his telescope (albeit a different kind of detector) found rings around Rhea.