The Marree Man is certainly big, 28km in circumference and ploughed into the plateau with the aid, surveyors suggest, of a satellite-linked global positioning system. One theory is the image was created by American service personnel from the nearby American satellite spy base, which was scheduled to close down at the end of the 20th century. The motive is still not clear, whether it is a "polite" thank you or an flying finger salute to their Australian landlords.