What is the moon halo and why does it appear

ArabiaWeather - Sometimes on cold nights, an amazing light halo may appear surrounding the moon, so what is the secret of this aura? And why do we see it?

The Lunar Halo is an optical phenomenon that usually occurs on cold nights when moonlight meets thin clouds in the upper layers of the atmosphere, loaded with small ice crystals through which the moon's light is refracted to reveal a wide luminous ring surrounding the moon.

Why do we see the lunar corona?

The ice has a hexagonal molecular structure that results in ice crystals in the form of hexagonal prisms, whose faces are tilted at an angle of 60 degrees. The smallness resulting from a 22-degree deflection of light is most common with the moon.

What are the ideal conditions to see the moon's corona?

In order for the conditions to be suitable for the formation of the lunar corona, the temperatures in the upper atmosphere must be low until the formation of thin clouds that carry ice crystals, at an altitude of more than 6000 meters, and the exact shape of the ice crystals and their direction is one of the basic conditions for the emergence of the lunar corona.

It should be noted that these halos can also appear around the sun when conditions are met.

Halos generally accompany many light phenomena, but the main image of the aura is that which is observed as a large circle whose distance from the center of light (the moon or the sun) ranges between 22 - 46 degrees, and when the angle is 22 degrees, the ring appears in white light, but when The phenomenon is severe and the angle of diffraction is greater, colors appear with the luminous ring, the inner color of the ring may be red with other colors inside the ring (orange, yellow, and rarely green), and in rare cases there may be a blue outer halo.