Crop circle is a circle or other geometric pattern formed in a field by the flattening of crops. Crop circles vary in size, but most of them are larger than 30 feet (9 meters) in diameter. Some of them measure more than 100 yards (90 meters) in diameter. Crop circles often appear overnight, without obvious evidence that they were made by people. Early crop circles were simple disks, but crop circles soon became more complex in shape. Some people believe that crop circles have unusual or even supernatural causes, such as freak weather events or landings by alien spacecraft. However, most scientists think that pranksters are making the circles.
People have noticed odd circles in the fields of England since the 1600’s. At that time, many people believed the Devil was responsible for creating the figures. In the late 1970’s, crop circles began to appear frequently in the English countryside. They have since spread around the world.
Several people have admitted to making crop circles, using a board attached to a rope to flatten crops. Even so, some experts think that certain crop circles have natural causes. They believe that the crops can be flattened by short-lived whirlwinds, called dust devils, or natural discharges of static electricity. Other people claim that crop circles are messages left by alien spacecraft. Still others believe that crop circles have magical causes. Skeptics argue that there is no reliable evidence for such claims.