PETROZAVODSK

Opening

Before dawn on 20 September 1977, people in Petrozavodsk, in Soviet Karelia, saw an enormous glowing object in the sky, shaped like a jellyfish, with rays spreading downward like tentacles. It hung over the city for minutes, then faded. Reports came in from across north-western Russia and Finland. The Soviet news agency TASS ran a report, which was unusual in itself, and scientists were asked to explain it. The explanation turned out to be a secret one: a military satellite launch from the Plesetsk cosmodrome, a few hundred kilometres away, at almost exactly the same time.

Timeline

20 September 1977, about 04:00Witnesses in Petrozavodsk see a bright star-like object grow into a jellyfish shape with luminous rays. It hovers, then moves toward Lake Onega and fades. Some witnesses report small holes in window glass afterward.

The same morningSimilar lights are reported from Leningrad, Helsinki, and elsewhere in the region.

Days laterTASS publishes a report describing the "unknown natural phenomenon," written by local correspondent Nikolai Milov.

1977 to 1978The Soviet Academy of Sciences examines the event. The launch of Kosmos-955 from Plesetsk that morning becomes the leading explanation among scientists, though the launch itself can't be discussed openly.

1978The Soviet government sets up a classified research programme into unusual aerial phenomena, partly in response to Petrozavodsk.

Key figures

Nikolai Milov wrote the TASS report that turned a local sighting into national news.

Soviet scientists, including Yuli Platov, later linked the sighting to rocket launches from Plesetsk, part of a long pattern of launch-related "UFOs" in the region.

Physical and documentary trail

What exists: the TASS report, eyewitness accounts from several cities, published Soviet and later Russian analyses, and the Kosmos-955 launch record.

The window holes are the only physical claim. They were reported locally, and no widely cited test connects them to the event.

Things you might not know

• It lasted 10 to 15 minutes. One astronomer followed it through a telescope for a quarter of an hour.
• Researchers gathered 85 reports. That was the total collected by Soviet scientists by the end of 1978.
• Lights were seen from Lithuania to the White Sea. Reports came from towns including Medvezhyegorsk, Kovdor, Kem, Priozersk, Valday and Palanga.
• Estimates of its size were huge. One witness described an airship-like object 100 metres long; one scientific model implied a core a kilometre across.
• The secret research had a name. The programme set up afterwards was called Setka.
• A scientist backed the rocket answer in 1984. Yuli Platov of the Soviet geomagnetism institute IZMIRAN endorsed the explanation that it was the exhaust of a satellite launch.

Competing explanations

A rocket launch. Kosmos-955 was launched from Plesetsk at about 04:01 local time. A rocket's exhaust, lit by sunlight high above the dark ground, produces exactly this kind of jellyfish shape with rays. Soviet launches were secret, so witnesses had no way of knowing. This is the standard explanation.

An unexplained phenomenon. Some researchers point to reports timed before the launch and to details such as the rays reaching the ground. Witness timings in the dark are rough, and a few minutes' difference is expected.

Later life of the case

Petrozavodsk is the case that started official Soviet UFO research, and it's a textbook example of a secret space launch creating a mass sighting. The same effect has since been seen worldwide after rocket launches.

Finding

A rocket launch. The time, the place, and the appearance all match Kosmos-955, and the Soviet secrecy that stopped anyone saying so at the time also explains why it looked like a mystery. The timing complaints are within the error of people describing the sky at four in the morning.

What still will not resolve: the window holes, if they were real and if they had anything to do with that night.