Reconstruction of the
Northdowns 13-08-2010 formation

1. Draw a circle. Draw and extend the horizontal and vertical centerlines.

2. Construct the inscribed heptagon (regular seven-sided polygon) of circle 1, pointing up.

3. Construct a circle centered at the righthand intersection of circle 1 and the horizontal centerline, tangent to the nearest side of heptagon 2, as shown.

4. Construct a circle concentric to circle 1, tangent to circle 3 at the righthand side.

5. Draw the seven "outer" diagonals of heptagon 2, connecting every second angular point.

6. Construct a circle centered at the leftmost intersection of diagonals 5 and the horizontal centerline, tangent to the nearest side of heptagon 2.

7. Copy circle 6 to the righthand intersection of circle 3 and the horizontal centerline.

8. Construct a circle concentric to circle 1, tangent to circle 7 at the righthand side.

9. Copy circles 3 and 7 as a whole six times, from the center of circle 3, the first pair to the righthand intersection of circle 7 and the horizontal centerline, the succeeding pairs to the corresponding intersections of the preceding ones, as shown.

10. Construct twelve circles concentric to circle 1, tangent to circles 9 at the righthand sides. See detail.

11. Construct a "two-points" circle (defined by the two end-points of a centerline) between the center of circle 6 and its righthand intersection with the horizontal centerline.

12. Copy circle 11 to the center of circle 1.

13. Construct two parallel, horizontal lines, tangent to circle 12 at both sides, extending to the outer circle 10 in both directions.

14. Construct the circumscribed heptagon of circle 1, pointing up.

15. Extend both sides of heptagon 14 intersecting the horizontal centerline up to the vertical centerline.

16. Construct a circle concentric to circle 1, passing through the intersection of lines 15.

17. Construct the circumscribed heptagon of circle 16, pointing down.

18. Draw the connecting line between the rightmost and upper lefthand angular points of heptagon 2.

19. Construct a circle concentric to circle 1, passing through the intersection of line 18 and the horizontal centerline.

20. Copy circle 19 to the lower angular point of heptagon 17, and move this circle (copy and delete original) to its lower intersection with the vertical centerline.

21. Copy circle 3 to the upper intersection of circle 20 and the vertical centerline.

22. Construct a circle concentric to circle 20, tangent to circle 21 at the upper side.

23. Copy circle 6 to the upper intersection of circle 22 and the vertical centerline.

24. Construct a circle concentric to circle 20, tangent to circle 23 at the upper side.

25. Copy circle 3 two times, to both intersections of circle 12 and the horizontal centerline.

26. Copy circle 6 two times, to the lefthand intersection of lefthand circle 25 and to the righthand intersection of righthand circle 25 with the horizontal centerline.

27. Construct six parallel, vertical lines, tangent to circle 12 at both sides, to lefthand circles 25 and 26 at the lefthand sides, and to righthand circles 25 and 26 at the righthand sides, and extend these lines downwards to circle 20. See detail.

28. Circles 1, 4, 8, 10, 20, 22 and 24, and lines 13 and 27, are used for the final reconstruction.

29. Remove all parts not present within the formation itself.

High resolution dwf-file

30. Colour all areas corresponding to standing...

High resolution dwf-file

31. ...or to flattened crop, and finish the reconstruction of the Northdowns formation of 13-08-2010.

High resolution dwf-file

32.
Courtesy the Crop Circle Connector
Photo by: John Montgomery
The final result, matched with the aerial image.