Most experts agree that Saturn is a giant ball of gas without a solid surface, though it does appear to have a hot inner core of iron and rock. Partially due to this, Saturn has flat poles and bulges at the equator. As the planet approaches summer, jet streams circulate to create vortexes similar to hurricanes on Earth.
Cassini's camera revealed a hexagon-shaped vortex above the planet's northern hemisphere that circulates hundreds of miles above in the stratosphere layer.
"The edges of this newly-found vortex appear to be hexagonal, precisely matching a famous and bizarre hexagonal cloud pattern we see deeper down in Saturn's atmosphere," said Leigh Fletcher, senior research fellow in planetary science at the University of Leicester, U.K. "While we did expect to see a vortex of some kind at Saturn's north pole as it grew warmer, its shape is really surprising. Either a hexagon has spawned spontaneously and identically at two different altitudes, one lower in the clouds and one high in the stratosphere, or the hexagon is in fact a towering structure spanning a vertical range of several hundred kilometers."