Mystery surrounds an eerie flash of light that spectacularly lit up a Russian city’s night sky.
Residents in Stavropol have been left seriously spooked by the huge white and blue burst that shot upwards into the air on Monday night.
The astonishing incident was caught on a car’s dash camera.
Scientists have so far been unable to explain its cause, but have ruled out that it was caused naturally.
“This flash cannot have been natural,” Svetlana Solovyova, chief analyst at the Stavropol Meteorological Center told ABC News.
“It wasn’t a meteorological event. There wasn’t a storm. More likely it is something made by a human being,” added the center’s Natalya Klimenko.
Several theories have now emerged as to its cause, according to RT.com.
Some have speculated that it was part of a military exercise, while others pointed to aliens who were documenting the area.
A more rational explanation, however, has been put forward by another meteorologist.
Yuri Varakin said it may have been caused by a special high-powered projector lamp used at Stavropol Airport to measure the height of clouds.
He claimed the burst of light is turned on when there is heavy cloud, which causes the widespread illumination.