By Benjamin Radford, Callum McKelvie last updated January 27, 2022

Crop circles that mysteriously appear in farmers' fields have puzzled experts and sparked UFO theories.

A crop circle in a field outside the village of Avebury, Wiltshire, England

Crop circles — strange patterns that appear mysteriously overnight in farmers' fields and often attributed to aliens or UFOs — are not simply the wild fantasies of Hollywood directors. No, Crop circles are real. This phenomena provokes puzzlement, delight and intrigue among the press and public alike. The circles are mostly found in the United Kingdom, particularly in South-West England according to BBC Travel, but have spread to dozens of countries around the world in past decades. The mystery has inspired countless books, blogs, fan groups, researchers (dubbed "cereologists" according to Pacific Standard and even Hollywood television series and films such as The X Files and M Night Shyamalan's Signs.

Despite having been studied for decades, the question remains: Who, or what, is making them?

ARE CROP CIRCLES A RECENT PHENOMENON?

A woodcut pamphlet that some claim represents an early crop circle.

Many people believe that crop circles have been reported for centuries, according to The Smithsonian Magazine.

Their primary piece of evidence is a woodcut from 1678 that appears to show a field of oat stalks laid out in a circle, according to The Independent. Some take this to be a first-hand eyewitness account of a crop circle, but a little historical investigation shows otherwise.

The chapbook itself, entitled The Mowing Devil (according to Oxford Reference), illustrates a folklore legend, in which an English farmer told a worker with whom he was feuding that he "would rather pay the Devil himself" to cut his oat field than pay the fee demanded. The source of the harvesting is not unknown or mysterious; it is indeed Satan himself, who — complete with signature horns and a tail — can be seen in the woodcut holding a scythe.

The Crop Circle, which appeared at Stonehenge, Wiltshire, England in 1996. (Image credit: Getty/ Heritage Images / Contributor)

In fact, the first real crop circles didn't appear until the 1970s, when simple circles began appearing in the English countryside. The number and complexity of the circles increased dramatically, reaching a peak in the 1980s and 1990s when increasingly elaborate circles were produced, according to an article by Nature, including those illustrating complex mathematical equations.

In July 1996, according to Harry Eilenstein in his book Crop Circles for Beginners, one of the world's most complex and spectacular crop circles appeared in England, across a highway from the mysterious and world-famous Stonehenge monument in the Wiltshire countryside. It was an astonishing fractal pattern called a Julia Set, and while some simple or rough circles might be explained away as the result of a strange weather phenomenon, this one unmistakably demonstrated intelligence. The only question was whether that intelligence was terrestrial or extraterrestrial.

Making the design all the more mysterious, it was claimed that the circle appeared in less than an hour and during the daytime, according to BriteEvents — which, if true, would be virtually impossible for hoaxers to accomplish. The circle became one of the most famous and important crop circles in history.

WHAT CREATES CROP CIRCLES?

Crop Circles have often been thought to be caused by UFOs.

Unlike other mysterious phenomenon such as psychic powers, ghosts, or Bigfoot, there is no doubt that crop circles are "real." The evidence that they exist is clear and overwhelming. The real question is instead what creates them — and there are ways to investigate that question.

We can look at both internal and external evidence to evaluate crop circles. Internal information includes the content and meaning of the designs (is there anything that indicates that any information contained in the "messages" is of extraterrestrial origin?), and external information, including the physical construction of the crop designs themselves (is there anything that indicates that the designs were created by anything other than humans?)

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