IN SOME remote polar regions, the ground is decorated with mysterious circles, polygons, islands and stripes made from stones. Puzzled scientists have proposed many mechanisms to explain their origin, but no one could account for all of the different shapes.
Now Mark Kessler and his colleagues at the University of California, Santa Cruz, have developed a computer model that can reproduce all the patterns (Science, vol 299, p 380). “The processes were identified before, but no one had successfully put them together,” says Rorik Peterson of the University of Alaska, who also studies the patterns.
Starting with bare soil…
