Menzel claimed to have his own UFO experience on 3 March 1955 while returning from the North Pole on the daily Air Force Weather "Ptarmigan" flight. His account is in both Menzel & Boyd and Menzel & Taves, in which he identified the 'flying saucer' he observed, as a mirage of Sirius (Steuart Campbell claimed that it was a mirage of Saturn). Menzel often explained that atmospheric hazes or temperature inversions could distort stars or planets, and make them appear to be larger than in reality, unusual in their shape, and in motion.