The moon halo diameter is calculated using the trigonometric formula, where the diameter of the halo is equal to the product of the moon's altitude and the constant 1.22.
The moon's altitude is a crucial factor in calculating the halo diameter because it determines the angle at which the moon's light enters the ice crystals in the atmosphere, creating the halo effect.
No, the moon halo diameter can vary depending on the location of the observer and the atmospheric conditions. It is most accurately calculated at locations near the equator with clear skies.
Moon halos occur relatively frequently, typically once or twice a month. However, they may not always be visible due to cloud cover or other atmospheric conditions.
Moon halos can be seen at any time of day or night, as long as the moon is above the horizon and the atmospheric conditions are favorable. However, they are most commonly seen during the late evening or early morning when the moon is closer to the horizon.