PARIS (75) 20.05.2017

On Saturday 20 May 2017 between 20:00 and 21:00, a witness noticed a bright point in the Paris sky. Through binoculars its light seemed to come from an oblong silvery-gray shape, apparently stationary for the 15-second observation. Only one account was collected. The probable explanation is a brief mirror-like reflection of sunlight from an aircraft. He initially thought of an approaching airplane with its headlight aimed at him, but the point seemed stationary and solid, like a metallic body. The proposed aircraft was at an elevation of 20–30°, perhaps 20–30 km away, in a clear sky. In 15 seconds it would travel about 3 km. For sideways motion relative to the line of sight, that gives an angular change of 6–9°, depending on distance, which the investigation considers difficult to detect. He described the binocular view as an oblong silvery-gray form with brightness and color like the daytime Moon, some darker regions and a small circular dark area. The Sun was on the west-northwest horizon and many aircraft were southeast. One could have been oriented so its fuselage reflected sunlight directly toward him. This precise geometry among Sun, observer, aircraft position and heading produces a very bright but fleeting reflection, seen only as a point without binoculars at that distance. Binoculars resolved the point, confirming it was not a star. The oblong form would be the fuselage; the darker circular area probably the wing seen edge-on from the observer's side and its attachment to the fuselage. This differently oriented structure would not reflect the Sun in the same way and would overlap the bright fuselage shape. The investigation considers this an ordinary aircraft misidentification. GEIPAN classifies the case B: observation of an aircraft.