Sighting in Rueil-Malmaison, August 23, 2018

Late in the evening, at 11:44 pm, a witness noticed a luminous patch above the clouds, first blue and then a yellowish-orange. Surprised, they had time to take a photo and a video, which intrigued them even more. The patch was at first stationary, then began to move. No particular noise was heard during the observation, which lasted about thirty seconds. The witness's wife also saw the phenomenon, though for a shorter time. Only one witness account was collected.

The investigation examined the hypothesis of a confusion with the light spots cast by ground-based searchlights of the "Skyrose" type onto a low cloud layer. The elongated shape, made up of several grouped elements, and the blue colour are typical of such spots. The yellow-orange colour is probably explained by coloured filters, interchangeable at will, fitted at the projector output. The lack of noise and the sweeping movements also fit. The date, a Thursday, fit less well, but use at a private party or for testing could not be ruled out. A low cloud layer, at about 200 m altitude, was confirmed.

The witness believed the phenomenon was behind the clouds, most likely because they had never seen such spots before: they are not beneath the clouds but on their base, visible only because the beams strike the water droplets. A plausible location for the projectors was identified, the Manoir du Paris Country Club complex, in line with the beam visible on the witness's photo, although their presence could not be confirmed. GEIPAN classified the case as B: a fairly strong probability of ground-based projector light reflected on the cloud layer.