Venus has a second wind. Not only do winds whip around our planetary neighbour’s equator, they also blow from the equator toward the poles, something never conclusively observed before. Their existence could help solve the biggest mystery about the planet’s atmosphere: how it rotates so quickly.
Venus rotates once every 243 Earth days, but its atmosphere does so every four days, with wind speeds in excess of 400 kilometres per hour parallel to the equator. Energy from sunlight is needed to maintain this frenzy. But with more sunlight hitting near the equator than at the poles, it wasn’t clear how enough energy could arrive where it was needed.
The newly detected meridional winds, blowing at a relatively leisurely 80 kilometres per hour, could pull some of that energy away from the equatorial regions, spreading it more evenly throughout the atmosphere.