UFO seen by soldiers in Cassis in 1977

Summary

In October 1977, two soldiers on duty in Cassis (France) observed an oval-shaped object in the sky. The object moved slowly from north to south, ascending and descending while leaving a glowing trail. The observation lasted between 5 and 7 minutes, and no sound was heard during the time. Initially thought to be weather balloons, this case did not match known patterns. The GEIPAN classified it as "C", suggesting a conventional explanation, although none was confirmed. The detailed description and lack of noise add mystery to the event.