Steve Alexander was flying over the site and took this picture in August of this year..
Awe... you guys beat me to it. I just spent the summer in Peru, btw. :)
I was personally given a tour of one of the $100,000+ tractors that are commonly in use by farmers these days. They incorporate some rather fancy GPS positioning software that can allow the technologically-savvy farmer to create these images should he/she be inclined to do so.
That said, I would suggest that this ghosting effect (and radiation checks) should be good litmus tests for weeding out the fakes from the real thing, if you will.