Sighting in Champigny-sur-Marne, July 4, 2023

At around 5 a.m., the witness was getting ready to leave home when they noticed a phenomenon in the sky that they compared to a "slow explosion". They watched it from their home for about ten minutes. It was amber yellow and its brightness kept increasing. The luminous "patch" changed shape but did not move. The witness took three photographs. Theirs was the only account collected, and the GEIPAN rated it as consistent.

The photographs were of poor quality and hard to use. One of them nevertheless helped pin down the azimuth and elevation of the sighting.

The investigation established that the witness had seen the Moon, full and at perigee, partly hidden by clouds. Several points support this: the amber yellow colour and strong brightness, which are often reported in such sightings; the Moon's azimuth, reconstructed with the Stellarium software, matching exactly that of the phenomenon measured on the photograph; a duration of about 10 minutes with no movement visible to the naked eye, which is typical of an astronomical object; and a round shape like the Moon's, with clouds passing in front of it from time to time. The strangeness the witness felt came from the unusual look of the Moon: its colour, strong brightness, size and partly masked shape. The case is classified A, observation of the Moon.