Moscow, Russia. A rare paraselene phenomenon was observed overnight over Moscow and the surrounding region, creating the appearance of multiple moons in the night sky.
Rare optical illusion observed
The paraselene, an optical illusion in which multiple Moon disks appear, occurs when light from the Moon is refracted by flat ice crystals high in the atmosphere. Icy hexagonal crystals suspended in the upper atmosphere refracted and reflected moonlight, producing glowing spots, or “mock moons,” on either side of the lunar disc.
Conditions over Moscow
Freezing temperatures and thin layers of high-altitude ice clouds over Moscow contributed to the conditions associated with the display. While such phenomena are more frequently seen in polar regions, the appearance of a distinct paraselene over a major urban centre is less common.
Related phenomena and safety
The paraselene is in the same family as “sun dogs,” which produce similar effects around the sun during daylight. Meteorologists and astronomers said the visual effect poses no danger and illustrates how light interacts with cold atmospheric layers.
Have you ever witnessed a paraselene or similar atmospheric optical phenomenon in your area?