One of the many surprises revealed by space probes studying Saturn was the existence of a hexagonal ring around Saturn’s south pole.  What impressed observers was the near-perfect regularity of the structure, and it’s persistence.  Several months ago, Urban Astronomer reported on experimental work by a team of physicists at the University of Oxford in which they recreated the hexagon in a laboratory.  Their work confirmed the theory that the shape was created by stable patterns of vortices within the atmosphere, and they were able to create different shapes in their experiment by adjusting the flow speeds of the different layers in their tank.

Now we can see the same effect occurring naturally here on planet Earth.  This photograph of Hurricane Isabel reveals a beautifully structured pentagon at the eye of the storm.  It turns out effects like these are present everywhere, if only you look for them.

With thanks to Emily Lakdawalla from the Planetary Society