Mysterious light identified as ISS in France

Summary

On July 23, 2017, a witness in Lannion, in the Côtes-d'Armor region of France, observed for less than a minute a bright white point slowly moving from west to east across a clear sky. The object gradually decreased in brightness as it progressed. Although only one witness was involved, their testimony was extremely precise in terms of time and exact sky position. After analysis, the GEIPAN team determined that the observed phenomenon corresponded to the passage of the International Space Station (ISS) across the sky. This type of identification is common in cases where space objects visible from Earth are mistaken for unusual phenomena.

The ISS is often visible to the naked eye when it passes through its orbit, especially during nighttime hours. In this case, the witness saw the station at its brightest point, near the southeast, and then watched it disappear toward the east, gradually losing intensity. This exact match between the observation and astronomical data led the GEIPAN to classify the case as "A," meaning a fully explained observation. This example shows how tools like Calsky can accurately identify unusual-looking objects in the night sky.