GROSLAY (95) 03.09.2021

On 3 September 2021 at about 18:30 in Groslay (95), a witness noticed a small black point apparently very high in the sky. It seemed stationary, with no reflections or other lights. The sky directly behind it was clear, with no cloud there at that moment. It looked rather round and very dark, described as metallic black, to the southwest. It seemed to have appeared suddenly, without leaving a trail or smoke. He watched for at least 30 seconds, after which it appeared to move very slowly westward. GEIPAN considers the amount of reliable, objectively supported information good: a single witness who completed the questionnaire carefully. There was no photograph or video of the UAP, but he reconstructed the scene on a photograph. This assessment concerns the quantity of such information collected for an account. The investigation found that he very probably observed a balloon, which he had himself considered; see the report. The round shape fits, a backlit balloon could appear dark, and its slow movement matched the wind. GEIPAN explains the perceived anomalies as follows. Sudden appearance and disappearance can result from a very small object being at the limit of visibility. Apparent immobility can arise from nearby clouds: the UAP seems still while clouds appear to move, although the source states that the reverse is occurring. Classification A: observation of a balloon.