COUDEKERQUE-BRANCHE (59) 13.08.2016

On August 13, 2016 at 01:30, a father and his two sons lie in their city garden to look at objects from the sky (shooting stars, satellites, planes...). Their attention is suddenly drawn by the rapid and silent passage of a triangular phenomenon of light red, orange colour, without a trail or halo. The luminous intensity of the UAP is rather subdued. The trajectory is straight. The UAP disappears completely after 6 to 8 seconds of observation. Only one testimony is collected. The evidential strength is good with a very detailed questionnaire, a very cooperative main witness with whom GEIPAN was able to exchange easily. An investigation and an interview with the main witness was carried out on site. All angular measurements and testimonial data are present and could be used for analysis (see the investigation report). In conclusion, we have shown in this analysis that the witnesses probably observed a barn owl flying over the block of houses including their garden. This conclusion is based on the following: - the colour described as light red or orange is that produced by reverberation of the orange lights of street lamps on the white plumage of the bird. - the shape, described as triangular but which, in view of the drawings made by one of the children of T1, is more like a three-pointed star, representing the tail and two wings of the bird. The fact that this shape does not change during the few seconds of observation is consistent with the preservation of this shape during the bird’s gliding flight. We also verified that a barn owl can glide with its tail closed, keeping its wings in the same position as in flapping flight. However, some uncertainty remains as to the orientation of its wings, which is perhaps more directed forward on the drawing made by one of the witness's sons than in reality. - the brightness, described by T1 as “subdued, not harsh, very soft”, fully in line with what a reflected light produces. - the total absence of noise. The barn owl is known to be very silent in flight. - the straight path, the short observation time, the absence of a visible halo or trail are compatible with gliding flight. - after calculations of observation distance, dimensions and speed estimates, the final results, very sensitive to T1 estimates (apparent size, observation time, final angular height) remain compatible with the bird hypothesis, and specifically a barn owl, gliding across the sky at a modest distance of around 20 m from the witnesses. The difference between the actual altitude and estimated by T1 is considerable but we have identified 3 factors that may have prevented T1 from estimating it correctly: - surprise effect, - prior concentration on observing distant objects, - the brevity of the observation, - the barn owl is present in the area and probably nests nearby, in an attic, a bell tower or in the attic of a building, which confirms a likelihood of the hypothesis. The observation, after analysis, is finally less strange. The main strangeness of the case, namely the rapid and progressive disappearance of the UAP, was able to find an explanation related to the configuration of the places. The street lamps surrounding the house block produce reverberation and some light pollution that spread through the air. This reverberation is stopped by the roofs of the houses creating an “oasis” of shade at the level of the gardens to a certain altitude. The owl moved about 20 m away from the witnesses, at an altitude initially outside that shade zone. During the glide, its trajectory was probably slightly descending then, at about 45° elevation, it entered the shade zone, probably by steepening its descent towards the houses which did not allow the witness to find it, thinking that it would continue to fly at its initial altitude. It is also possible that the visibility at this point is limited (tree) or that the brevity of the observation does not allow the witnesses to realize that the owl is returning to the reverberation zone. The account has good evidential strength, however, which is based solely on the observation of the main witness (no photos or videos, and normal difficulty of appreciation of distances, altitudes and dimensions in the sky). As a result, the GEIPAN classifies this observation as "B", probable misidentification of a bird, potentially a barn owl reflecting city lights while gliding over the block of houses and gardens where the witnesses were.