MOULEZAN (30) 26.12.2018

On 26 December 2018 at 06:45, a witness having breakfast in his living room noticed an object moving in the sky. He thought it was a satellite but was surprised by its size. Going outside, he saw 4 luminous points suggesting a square shape. The object moved south/southwest to east without any particular sound. Initially straight, its path began to “undulate,” then made a long turn before it was lost from view. He very probably saw the International Space Station (ISS). He thought it was a satellite, “but it was bigger.” The ISS does indeed appear larger and brighter than an ordinary satellite. Its path that morning matches the southwest-to-east description in the exact observation interval (see attached trajectory record from www.calsky.com). The appearance matches many GEIPAN accounts; see www.geipan.fr, search term ISS, and the explanatory video “A satellite or the International Space Station (ISS).” Some such accounts also report a curved path. A satellite that does not pass directly overhead genuinely follows a curved apparent trajectory. Near its highest point, here 40°, perceived by the witness as “almost overhead,” its path can also be misperceived: the higher it is, the harder it is to track its position and movement relative to north, east, south and west. Apparent oscillations are also familiar and correspond to the autokinetic effect when viewing a point of light in darkness (see the article on that effect). One peculiarity is the report of multiple distinct points, now described by the source as exactly 5, although the opening account says 4. The source gives normal human angular resolution as about 1/60 degree, or 1/3,600 radian. At a distance of 400 km, points would have to be over 100 m apart to be resolved. The ISS spans about 100 m, so in theory individual points within it should not be distinguishable. However, resolution depends on the observer, who may perform above average, and the radiometric contrast, particularly strong against this dark background. A factor of 2 or 3 improvement over standard resolution could explain several more reflective points on the station being seen. The presence of 4 accompanying resupply spacecraft (see attached satellite record) does not explain the 5 points, because they were docked, except perhaps 1 at a particular moment, and did not increase the object's overall size. This peculiarity is not fully explained but does not rule out the hypothesis. The ISS was then almost as bright as Venus. GEIPAN considers it hardly possible that the witness saw another UAP without also noticing the ISS, which would have been close by, moving similarly at the same time. GEIPAN therefore classifies the case A: very probable observation of the ISS.