IncidentThe Petrozavodsk Phenomenon (20 September 1977)

Around 4 am local time, witnesses reported a large bright ‘star’ that flared, moved toward Petrozavodsk, and expanded into an enormous ‘jellyfish’ showering the city with very fine rays ‘like pouring rain,’ then changed into a bright semicircle and faded over ~10-12 minutes; sightings spanned from Helsinki and Copenhagen deep into the USSR. TASS reported it (itself unusual for the controlled Soviet press), and the Soviet Academy of Sciences initially said the phenomenon could not be satisfactorily understood. US analyst James Oberg phoned NASA’s satellite-tracking center, confirmed a Vostok-2M launch of the Kosmos 955 electronic-intelligence satellite from Plesetsk (~350 km east) minutes before the sighting, and tied the display to the rocket’s expanding exhaust plume lit by sunlight at high altitude while the ground was still dark; Soviet scientist Yuli Platov endorsed the rocket explanation in 1984. A famous Soviet-bloc mass-sighting reported even in the censored press and credibly resolved to a Plesetsk launch - adding USSR/Scandinavian breadth and another clean ‘rocket launch misidentified as a giant UFO’ case alongside the Canary Islands Poseidon and the Greifswald flares; Plesetsk launches repeatedly seeded such flaps across northern Europe.