Petrozavodsk Phenomenon (the Petrozavodsk Jellyfish)

Petrozavodsk is the capital of Karelia, on the western shore of Lake Onega. On 20 September 1977, before dawn, most of its residents were still asleep. About 100 of them were not.

It began around 4 a.m. A huge "star" flared up in the dark sky. It pulsed, sending shafts of light toward the ground. TASS correspondent Nikolai Milov described what came next: "This star moved slowly towards Petrozavodsk and, spreading out over it in the form of a jellyfish, hung there, showering the city with a multitude of very fine rays which created an image of pouring rain."

Dockworkers on the early shift saw it. So did police officers, sailors and an ambulance crew. At Pulkovo Airport in Leningrad, air traffic controller B. Blagirev watched a fireball slightly larger than Venus, "surrounded by a spacious, rhythmically glowing coat with intricate structure." He said it had "nothing similar to aurora." Writer and amateur astronomer Yuri Linnik turned his telescope on it. He saw a lens-shaped object with "a color of a dark amethyst, intensively lightened from inside."

Then it changed. It became "a bright half-disk" and headed out over Lake Onega. Witness Dmitry Svintsov saw it shift "from a sphere to a triangle" before it vanished near the Ivanovsky islands. A round depression formed in the clouds. It was bright red in the middle and white on each side. The whole display lasted 10 to 15 minutes. It made no sound at all.

Local historian Nikolai Kutkov records that taxi drivers at the railway station feared a neutron bomb. They fled and broke into a wine shop, believing alcohol protects against radiation.

On 23 September the TASS report appeared in Sotsialisticheskaya Industriya and Izvestiya. Reports came from as far west as Copenhagen and Helsinki and as far east as Vladivostok. Governments of northern European countries asked Academy of Sciences President Anatoly Aleksandrov whether the USSR was testing weapons.

On 20 October 1977 astronomer L.M. Gindilis and his colleagues delivered a preliminary finding: "based on the available data, it is unfeasible to satisfactorily understand the observed phenomenon." That October a Kremlin meeting created two state research programmes. Setka MO belonged to the Ministry of Defence and Setka AN to the Academy. They ran from 1978 to 1990 and were extended to 1995. Psychologist E.K. Andreyeva examined nine witnesses and vouched for their "complete mental sanity." From October 1977 to February 1978, about 15 residents reported holes in their windows. A forensic examination blamed a slingshot, a gas pistol or an air rifle.

That same morning, at 01:01 UTC, a Vostok-2M rocket lifted off from Plesetsk, northeast of the city, carrying the satellite Kosmos 955. The USSR only publicly acknowledged the launch site in 1983. James Oberg argued that people in Petrozavodsk had been watching the exhaust from behind. The Academy's researchers eventually attributed the event to the launch.

Critics were not convinced. Felix Ziegel argued that the westward motion contradicted a northeast launch. Oleh Pruss knew rocket launches firsthand, and he insisted: "there was something completely different over Petrozavodsk." In 1978 a Petrozavodsk State University study placed the object at 6 to 15 km altitude. That did not fit a rocket.

Petrozavodsk became the textbook early example of the "space jellyfish." Similar shapes have since appeared after launches from Plesetsk and of Falcon 9 rockets. Oberg himself compared it to a 2015 Falcon 9 display.