A series of celestial phenomena of disputed nature was observed in the western Soviet Union, Finland and Denmark.

Petrozavodsk phenomenon

Series of disputed celestial events (1977)

The Petrozavodsk phenomenon was a series of celestial events of a disputed nature that occurred on 20 September 1977. The sightings were reported over a vast territory, from Copenhagen and Helsinki in the west to Vladivostok in the east. It is named after the city of…