From a distance, the planet Saturn looks majestic, tranquil.
Don’t be fooled.
When seen through a telescope from Earth, the ringed planet looks stately and serene. But when the robotic spacecraft Cassini crossed almost a billion miles of space to get up close, it found something very different.
It turns out that the clouds of Saturn are seething with whirlpools, currents, eddies—and sometimes huge storms.
A hurricane on Earth is considered strong if its winds reach 150 miles per hour. On Saturn the wind speed can pass 1,000 miles per hour. Some of the energy that drives that weather doesn’t come from the Sun, but wells up from the unimaginable depths inside the planet itself. Down there, the winds blow even faster.
Every once in a while, huge and violent storms break out. Late last year, Saturn explorers watching pictures from Cassini noticed a new storm forming. It soon grew to cover an area more than eight times larger than the entire surface of the Earth.
Saturn’s storms discharge powerful lightning, as much as 10,000 times stronger than on Earth. At its most intense, this latest storm generated more than 10 lightning flashes per second. A radio instrument on board Cassini was even able to capture sounds from the bolts.
But there’s another storm on Saturn.
The monster of them all.
The south polar vortex.
The winds at the pole tear around the center at 350 miles per hour. Such a well-defined, hurricane-like storm has never been seen before outside of Earth, and Saturn explorers are fascinated by the mysterious dark clouds at the base of the whirlpool. This is a truly massive cyclone, hundreds of times stronger than the most giant hurricanes on Earth. Cumulus clouds twirl around the vortex, rising two to five times taller than the clouds of terrestrial thunderstorms, betraying the presence of even more storms lurking beneath.
This is an actual photograph of the vortex, with the motion added, of course. Click or tap the image to see its approximate size in relation to the Earth.
This maelstrom spans 5,000 miles. Sometimes I think about the fact that this swirling monster is real. It’s out there right now. If you were at the south pole of Saturn near the cloud tops, you’d see thunderheads boiling and moving at hundreds of miles per hour, crackling with lightning, seething from horizon to far horizon. Day and night, forever.
To learn more: Cassini | NASA’s Solar System Explorer (Bonus experiment: get close to the screen and stare at the center of the vortex animation for a full two rotations. Then scroll up and look at one of the other pictures, or even the back of your hand.)