Latest Tuesday brought a rare atmospheric event to the sky over Russian city of Murmansk - nacreous clouds.
      
      Suddenly Murmansk dwellers noticed that gaps between clouds started glowing with bright rainbow colours. Scientists explain this event with formation of so-called nacreous clouds, which usually appears in upper atmospheric layers (20-30 km).
      
      In winter the Sun never rises too high and can illuminate these clouds, which become iridescent in response to various dynamic factors and optical effects.
      
      Source: Science News