Short answers, pulled from the story.
Saturn's hexagon is a persistent approximately hexagonal cloud pattern around the north pole of Saturn, located at about 78 degrees north latitude. Its six sides are each roughly 14,500 kilometres long, making every side about 2,000 kilometres longer than Earth's diameter. It stands about 300 kilometres high and may be a jet stream moving at 320 kilometres per hour.
David Godfrey discovered Saturn's hexagon in 1987 by assembling flyby images collected during the 1981 Voyager mission. The structure was revisited in 2006 by the Cassini-Huygens spacecraft.
Between 2012 and 2016, Saturn's hexagon shifted from a mostly blue color to a more golden hue, as observed by the Cassini spacecraft. One hypothesis is that the change in season exposed the north pole to sunlight, generating a photochemical haze that altered the color of the cloud pattern.
Saturn's hexagon rotates with a period of 10 hours, 39 minutes, and 24 seconds. This matches the period of Saturn's radio emissions from its interior, a coincidence that researchers have not fully explained.
One leading hypothesis, developed at Oxford University, proposes the hexagon forms at a steep latitudinal wind-speed gradient in Saturn's atmosphere. Laboratory experiments rotating liquid at different speeds produced similar polygons, most commonly six-sided. Research also shows that the north polar vortex plays a decisive role in stabilizing the hexagonal jet structure.
No. Hubble observations confirmed that Saturn's south pole does not have a hexagon. The south pole does have a vortex, but no polygonal cloud pattern has been observed there.