This table shows some of the main characteristics of crop circles and gives explanations for each of these. Characteristic Status UFOs Hoaxing Plasma Vortex Precise Definition Displayed by almost all circles Reports of precisely formed UFOs do exist but could be reports of Meaden Vortices. Can be produced by using pole and chain. Areas of ionised air can be precisely defined.
Snowflakes are also precisely defined.
Spaceships would damage the crop but could be creating wind effects. All known attempts damage crops Air pressure could create circles without damaging the crop. Some UFOs have been reported to rotate but these could also be accounted for by the Meaden Vortex. Could be created by using a pivot but would leave evidence of a central hole. A natural consequence of the Meaden Vortex.