Sighting in Marseille, March 31, 2018

On the evening of 31 March 2018, a witness standing on their balcony noticed a very bright ball of light showing a variety of colours. The sighting lasted about ten minutes, between roughly 9:30 and 9:41 pm. The object followed a downward path and slowly vanished behind the hill of Notre-Dame de la Garde. The witness compared it to a star slowly falling from the sky in slow motion. This was the only account collected.

The investigation concluded that the witness had seen Venus. Low on the horizon, the planet does appear to sink: over ten minutes its height dropped from about 2° to 0.5°, a slow movement that is nonetheless clearly noticeable close to the horizon. Its position (azimuth 283°) matches the description, slightly left of Notre-Dame de la Garde (290°) and right of Rigel (237°). The witness ruled out Venus, convinced it would be hidden by the hill. However, a reconstruction shows that the highest obstacle in that direction, 3,900 m away, stood at about 0.7° elevation. Venus, at 2°, was therefore visible, and it is normal that it disappeared once it had dropped to 0.5°. The changing colours are explained by atmospheric effects. The GEIPAN classified the case as A: Venus.