At night, when an observer notices a light appearing out of the darkness, he usually cannot see the object that produces or carries the light. Under familiar conditions on the ground or in the air he usually interprets the light correctly, by a kind of informed guesswork, as that of an automobile, an advertising sign, an airport beacon, a plane, a star, etc. But if it appears under unfamiliar conditions or in unexpected circumstances, he has to make an uninformed guess based on largely unconscious estimates of its size, distance, height, color, and rate of movement. To the driver of a car on a dark country road, a single light suddenly appearing ahead may indicate a plane or a star low in the sky or something on the road itself--a motorcycle, a car with only one headlight working, a workman’s lantern, a pedestrian carrying a flashlight, or something else. A double light may mean another automobile, two motorcycles traveling parallel, an animal whose eyes shine in the approaching headlight, or something else. The driver cannot be sure he interprets the light correctly until he passes it and can see the object itself or until he can identify it in some other way. _Michigan’s Flying Bird Cage_ A UFO sighting based on mistaken identification of strange lights occurred in the early morning hours of March 22, 1959, near Ann Arbor, Michigan. The night was clear, the moon was nearly full, and visibility was unusually good. At about 1:30 A.M. a man and his wife driving on a country road suddenly noticed a strange object hovering in the sky south of the road. According to their report to the Air Force, the UFO was an elongated oval with a dome on top, something like a bird cage, and brilliantly illuminated by two shafts of intense pale-yellow light that sprang from the bottom and converged over the top. Frightened at this apparition, the witnesses could provide only uncertain estimates of distance and size. The object seemed to be twenty to thirty feet in diameter, was at an altitude of about 200 feet when first seen, and was hovering about two miles away. As they drove on, the object seemed to move and travel parallel with the car for about a mile. Then the yellow lights dimmed and a circle of eight or ten red lights suddenly appeared on the underside, the UFO rose vertically, very rapidly, and vanished in a few seconds. It had been in view for a period of five to ten minutes.