Here's how it works:
1. Ice crystals: The high-altitude clouds contain tiny hexagonal ice crystals.
2. Sunlight enters: Sunlight enters the ice crystals at a specific angle.
3. Refraction: The light bends (refracts) as it passes through the ice crystals.
4. Reflection: Some of the light reflects off the internal surfaces of the crystals.
5. Angle of deflection: The light is deflected at a specific angle, creating a circular pattern around the sun.
What does it mean?
A halo around the sun isn't a sign of anything particularly unusual. It simply means that there are high-altitude clouds present with ice crystals that are the right size and shape to refract and reflect sunlight in this way.
Other things to know:
* Color: Halos often have a reddish hue on the inside and a bluish hue on the outside.
* Size: The size of the halo can vary, but a 22-degree halo (meaning the ring is about 22 degrees from the sun) is the most common.
* Other halo types: There are other types of halos, such as sun dogs (bright spots on either side of the sun) and mock suns (bright patches of light above or below the sun).
In short, a halo around the sun is a beautiful optical phenomenon caused by ice crystals in clouds, and it's nothing to be worried about.
