In St. Petersburg, night of 31/1 to 1/2: four moons

On the night of January 31 to February 1, a rare optical phenomenon was observed in the sky over St. Petersburg. People saw four moons at once. According to observers, this was a lunar halo with parhelia: light from the real Moon was refracted by hexagonal ice crystals in the frosty air, creating three bright false images, making it appear as if there were four lunar disks in the sky. The main lunar disk remained in its visible position, while the trio of artificial moons appeared to the sides.

Context

Such optical phenomena are rare and usually occur with high concentrations of frost-resistant crystals in cold air.