Epinay-sur-Seine 2015, Triangular shape observation

Summary

On May 4, 2015, a witness in Epinay-sur-Seine (France) observed a triangular shape in the sky at around 4 a.m. The object passed at low altitude with white, yellow, red, and blinking lights at its corners. The witness did not see a fuselage or wings, which made the object seem unusual. However, the GEIPAN classified the case as a probable airplane. The explanation points to an optical illusion known as "contour or shape illusion," where light points are interpreted as a defined object by those points.

Additionally, the Bourget Airport is only 7.5 km away, and wind direction indicated that planes were taking off westward, toward Epinay. Although the GEIPAN couldn't verify with air traffic control whether a flight occurred at that moment, the light pattern and sound matched a dark-colored military transport plane. This case illustrates how a nighttime observation can cause confusion when key visual details are missing.