Moon dog

One side is a moon halo phenomenon, which is caused by the refraction of moonlight on ice crystals in the troposphere.

Analogous to the sundogs, the phenomenon at a distance of approximately 22 ° on either side of the moon, and usually only at a coverage with cirrus or Cirrostratuswolken on, but it can in principle also of ice crystals at low altitude caused (eg Polar Snow ) be. Besides moons are rarer than sundogs, because the moon has a lower light intensity than the sun. Therefore, they are also usually visible only during a full moon.