The marks varied from five to seven inches wide, and the smallest circular mark was 31 ft., 9 in. in diameter. Three of the rings were essentially circular, with the largest mark being slightly elliptical, varying from 34 ft., 5 in. to 36 ft., 3 in. There were no exhaust blasts, scorch marks or disturbances of the soil, and vegetation within the circles had apparently been removed by the object that made the marks. The official investigation report implies that the marks were most likely left by a 135-ton aircraft or spacecraft.