The latest weird discovery in the solar system is a bizarre hexagon of clouds encircling the north pole of Saturn. Well, its not really a new discovery - it was first sighted about fifteen years ago by the spacecrafts Voyager 1 and 2. What is new is that the latest images by the Cassini spacecraft confirm that this is no short-lived phenomenon. Now, why did it take fifteen years to confirm this ? Well, the polar night on Saturn in winter lasts about fifteen years, and its only now that the north pole is re-emerging from darkness (The hexagon is currently visible mostly in infra-red but should become visible to visual cameras soon). The hexagon itself looks like a big bolt holding the top of a giant screw around which Saturn is rotating.So whats the big deal? The big deal is that natural hexagons do not occur that frequently in nature. Our planet has similar winds blowing in the poles, but they form circular patterns. Nature usually abhors polygons - it almost always prefers circles and ellipses - and the presence of an almost symmetrical six sided figure has intrigued scientists - is there something unnatural thats responsible for the hexagon ?
This thought is very exciting to astronomers - finding evidence of life outside Earth is sort of an holy grail for them, and any unexplainable abnormality is immediately used as an excuse to fantasize about extra terrestrials. Sadly, the hexagon shape is something that can be explained without the need for giant gas-beings building hexagonal cities in Saturn's atmosphere. Apparently rotating a bucket of water at high speeds produces geometric shapes - a three-sided star, a square, a pentagon - and at high speeds - a hexagon (read about this experiment at Nature). Something similar is probably at work in Saturn's atmosphere.
On a lighter note, John Tierney at the New York Times had a competition to find the whackiest theory for the hexagon (read the whole story at Tierney Lab - may need subscription). My personal pick is "It’s a gaseous planet . . . it has to have some place where it can find relief". Hah.
