'Four Moons' Spotted In Russia's Sky: What Is This Rare Phenomenon And The Science Behind It ?

People in St Petersburg, Russia, were left stunned after seeing what looked like four moons shining in the night sky. The rare sight was noticed on Sunday night, and soon photos and videos began spreading across social media.

At first glance, it seemed as if the Moon had multiplied, with bright glowing shapes appearing around it. Many skywatchers stopped to look up, amazed by the unusual and beautiful view.

What caused the "four moons" effect?

This striking display is known as paraselenae, also called a moon dog or mock moon. It is not a space event, but a weather-related optical illusion. The effect happens when moonlight passes through very thin, high clouds made of ice crystals.

These clouds, called cirrus or cirrostratus clouds, contain flat, six-sided ice crystals. When moonlight bends through these crystals, bright spots appear on either side of the Moon. This creates the illusion of more than one moon in the sky.

Why does it look so dramatic?

According to NASA, paraselenae usually appear about 22 degrees away from the Moon and are much dimmer than the Moon itself. They are easier to see when the Moon is low in the sky, as the softer light makes the glowing spots stand out more clearly.

The bright shapes always stay level with the Moon near the horizon. Their size and shape depend on how the ice crystals are arranged in the clouds. If the crystals are larger or move slightly as they fall, the light can stretch vertically and form glowing pillars.

As explained by Skybrary, bigger ice crystals often create taller and clearer light patterns, making the scene even more impressive.

For many residents, the rare sight was a moment of wonder-one that turned an ordinary night sky into a truly unforgettable experience.