An account in Vaucluse, France

On the evening of November 9, 2017, at around 10:25 PM, a witness from his home notices a particular luminous phenomenon in the night sky. The witness describes "a glowing cloud" then a luminous "beam." The observation lasts until 11 PM, with the "glowing cloud" gradually going out. The witness has time to take photographs. No other testimony is collected. The witness observed a rare optical phenomenon called a light column, or solar pillar or light pillar (Light pillar in English). This natural phenomenon occurs when sunlight or moonlight reflects off ice crystals suspended in the atmosphere. It is visible when the Sun or Moon is near the horizon. It also occurs with artificial lights such as streetlights. Indeed, the witness mentions "the reflection of a city's light." However, the light source on the ground must be fairly distant, because it is not directly visible. Street lighting provides light sources that can reflect off ice crystals suspended in the air in cold weather (the Carpentras weather station indicates 1.7°C that day) or in clouds, and produces light columns. In this case, it is the combination of a natural phenomenon (flat ice crystals located lower than usual due to cold weather at altitude) and an artificial one with the presence of strong point light sources on the ground that produces this photometeor. The light sources here may come from the city of Salon-de-Provence located to the southwest, like the phenomenon. For more information, see the article Light Column. Consequently, GEIPAN classifies this as A, as the observation of an atmospheric light column.