[Addendum: About a day after writing this, it occurred to me that people might assume it is some sort of April Fool's joke. Amazingly it is not. However, I have managed to discover a more plausible explanation for Saturn's hexagon.]
Remember the Cassini probe to Saturn and its moon Titan? Well, it's still going strong. The above image shows a distinct hexagonal formation directly above Saturn's north pole. The shape is 15,000 miles wide (large enough to encompass nearly four Earths). Apparently the Voyager probes had detected it on their flybys in the 80s, but this is the first time that the entire hexagon has been captured in a single image. And it confirms that this is a real longterm (perhaps permanent) phenomenon. What I find interesting is that so far, scientists haven't put forth even the most tentative theory as to how such a structure could form or maintain itself. (Obviously it was built by intelligent Saturnians.)
Saturn's south pole has a radically different, yet no less dramatic, appearance. It actually looks to have a form more appropriate to Uranus.