The phenomenon of seeing two suns in the sky is often referred to as a "sun dog" or "parhelion." Sun dogs are optical phenomena caused by the interaction of sunlight with ice crystals in the Earth's atmosphere. They typically appear as bright spots or patches of light on either side of the Sun, creating the illusion of multiple suns.
Here's how sun dogs are formed:
Ice Crystals: Sun dogs are created when sunlight passes through ice crystals, typically found in high-altitude cirrus clouds or in very cold regions of the atmosphere. These ice crystals can be hexagonal or plate-shaped.
Refraction and Reflection: As sunlight enters an ice crystal, it undergoes refraction, bending the light rays. The bent light then exits the crystal and can be further reflected internally within the crystal surfaces.
Angular Alignment: The specific angles at which the light enters and exits the ice crystals determine the formation of sun dogs. When the angles are just right, the refracted and reflected light can create a halo or bright spot on either side of the Sun.
The result is that, under certain atmospheric conditions, you may see two bright spots or patches of light located horizontally from the Sun. These spots are the sun dogs, and they often appear reddish in color due to the scattering of shorter wavelengths of light.
It's important to note that sun dogs are optical illusions caused by the interaction of sunlight with ice crystals in the atmosphere. They are not actual additional suns or celestial bodies. Sun dogs are relatively common but can still be fascinating to observe when the atmospheric conditions are favorable.