MIOS (33) 03.05.2018

On 3 May 2018 at 22:30, a witness noticed a stationary light low in a clear sky. He subsequently described movements left and right and up and down, together with color changes. No sound was heard. He filmed the observation, which lasted 3–4 minutes. Only 1 account was collected. GEIPAN concludes that he very probably observed Jupiter. Its southeast position at azimuth 123° and elevation 9° was reasonably close to his estimated 15° elevation. The point-like, steady-light appearance fits a celestial body. Changes involving white or yellow light, with occasional burst-like effects, fit atmospheric effects that alter color and can create halos, especially in high humidity. GEIPAN attributes the perceived movements—side to side, up and down, nearer and farther—to 2 familiar effects in observing stars. Autokinesis produces perceived angular motion; the source refers to the article “Raison et psychologie.” Atmospheric brightness fluctuations can also be interpreted as radial movement toward or away from the observer. GEIPAN attributes the end of the sighting to a passing cloud, and notes that Cap-Ferret station data show the sky was not completely overcast at the end of the day; see the reconstruction. It classifies the case A: very probable observation of Jupiter.