Massive 33-Related Crop Circle 4 Weeks Before 9/11

Milk Hill, Wiltshire, U.K., August 13, 2001 

This crop circle was discovered August 13, 2001 at Milk Hill in Wiltshire, U.K. Composed of 409 circles, the formation was 900 feet in diameter, flowing over an undulating landscape that rendered it impossible to see from one side of the formation to the other! Information encoded into the design specifies the date of its creation and the lat/lon of its position! How could human beings have created this design without being discovered?

 More here.

A "triskelion" formation-- 3 interlocked spirals, or 3 + 3 arms. The larger circles have 3 and 3 side circles.

No way humans made this. The question is-- who did and why???