Venus is not a placid paradise — that much we know. In addition to searing surface temperatures, wind in the upper atmosphere howls at up to 250 miles per hour, carrying clouds around the planet once every four days.

Yet Venus itself spins very slowly: one rotation every 243 Earth days — in the wrong direction, no less, opposite to almost every other body in the solar system.

[Read about the search for life on Venus and the detction of phosphine in its clouds.]

On the whole, the atmosphere on Earth rotates about the same speed as the planet. So why does the air on slow-spinning Venus speed around so much faster than the planet itself?

The Japanese space probe Akatsuki, now in orbit around Venus, seeks to solve the mystery of so-called super-rotation. Scientists working on the mission are presenting some of their early findings at a meeting this week of the American Astronomical Society’s Division for Planetary Sciences in Pasadena, Calif.