The appearance of such clouds, also called mesospheric clouds, is a rare atmospheric phenomenon.

      On the night of July 16, noctilucent clouds as if illuminated from the inside were witnessed in the sky of Barnaul.

      The nature of this phenomenon is studied; experts associate the appearance of silvery glow in the sky with the fact that the clouds are at a very high altitude, practically in the outer space. Due to this fact the sunlight reflects from the frozen mini crystals of water thus creates flickering of heavenly beauty.

      Earlier, rare luminous clouds were seen in the sky over Omsk.