One of the most bizarre weather patterns known has been photographed at Saturn, where astronomers have spotted a huge, six-sided feature circling the North pole.
Rather than the normally sinuous cloud structures seen on all planets that have atmospheres, this thing is a hexagon.
The honeycomb-like feature has been seen before. NASA's Voyager 1 and 2 spacecraft imaged it more than two decades ago. Now, having spotted it with the Cassini spacecraft, scientists conclude it is a long-lasting oddity.