With its clouds of sulfuric acid and a likely victim of runaway greenhouse effect, Venus is a planet akin to hell.

Despite being a toxic wasteland where the chance of life existing is next to zero, our planetary neighbor has been shrouded in mystery for decades – and it has to do with its bizarre atmosphere.

For some odd reason, Venus’ atmosphere spins at a much faster rate than the planet’s surface. Compared to Earth, Venus spins at a leisurely pace on its axis, with its surface taking 243 Earth days to complete one rotation. But the planet’s atmosphere twirls around nearly 60 times faster than its surface, completing one full rotation every 96 hours.

This phenomenon has become known as super-rotation, which was first discovered in the 1960s – but until now, scientists have been stumped on what really causes it.

For super-rotation to occur, which has also been seen on Titan, Saturn’s largest moon, the atmosphere of Venus has to have enough angular momentum to overcome the friction with the planet’s surface. But the source of this angular momentum – the amount of momentum a body possesses because of its spin rate – was still a mystery.

Scientists then began analyzing data from the Japanese space probe Akatsuki, also known as the Venus Climate Orbiter, that has been orbiting the planet since 2015. They focused on a super-rotation in a cloud layer near the equator that reached about 245 miles per hour.

Based on Akatsuki’s ultraviolet images and thermal infrared data, the scientists developed a way to track the complex cloud motions and the way heat circulated in the atmosphere.

With the data in hand, the team found out that the Venusian atmosphere received angular momentum via thermal tides, which are variations in atmospheric pressure, largely driven by solar heating close to the planet’s equator.

The scientists detailed their discoveries in the journal Science.

These important findings could also be used to shed light on the habitability of tidally locked exoplanets. These alien worlds have one side that always faces away from their star and one side that is constantly bombarded with sunlight. One side would likely be incredibly hot and freezing cold on the other, but super-rotation could, in theory, balance the temperature differences and provide a more suitable environment that could support life.

Ethen Kim Lieser is a Tech Editor who has held posts at Google, The Korea Herald, Lincoln Journal Star, AsianWeek and Arirang TV. He currently resides in Minneapolis.

Image: Reuters.