On the Periodicity of Crop Circles

Reports of crop circle sightings in Indonesia in the last few days got me thinking: What is the pattern to these patterns? Is there a pattern meta-pattern?

Enter Google News:

crop-circles.png

Every eight years. Whoa. King Minos of Crete had eight-year terms. Interesting.

Feel free, of course, to suggest other equally orthogonal things with eight-year terms.