What gives with Earth's nearest planetary neighbor? Sure, Venus looks bland and featureless when viewed through a telescope. (See for yourself: it's the unmistakably bright "star" low in the west after sunset.) But this veiled planet has challenged planetary scientists for decades.
Fifty years ago, radar observations confirmed that Venus is rotating very, very slowly (once every 243 days) and backward (retrograde) with respect to Earth. Then, in the 1970s, passing spacecraft showed that the planet's mid-level atmosphere is racing ahead of the planet itself at hurricane-like speeds, swirling around in just about 4 days. The planet's clouds form distinctive chevron shapes, a combination of this superrotation and the slow migration of gas from the Sun-warmed equator to the cooler poles. No computer model has yet explained why the atmosphere moves so fast — let alone why Venus spins the way it does.
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