About Sun halo:
- What is it? It is an optical phenomenon that occurs due to sunlight refracting millions of hexagonal ice crystals suspended in the atmosphere.
- How it is formed?
- When white light passes through unique hexagonal ice crystals found in upper-level cirrus clouds, causing the halo to have colours.
- The clouds contain millions of tiny ice crystals, which refract and split the light to give an impression of a circular rainbow ring.
- The crystals have to be oriented and positioned just so with respect to your eye, for the halo to appear.
- Light undergoes two refractions as it passes through the ice crystals and the bending that occurs depends on the ice crystal's diameter.
- The two refractions bend the light by 22 degrees from its original point, producing a ring of light around the Sun or the Moon.
- The lunar halos are mostly colourless as moonlight is not very bright.
- In the case of the Sun, these colours are more noticeable and appear as bright as a rainbow.
Q1) What are Cirrus clouds?
Cirrus clouds are a type of high-altitude cloud that are composed of ice crystals. They are thin, wispy, and often appear as long, white, feather-like clouds, stretched out across the sky. Cirrus clouds form at altitudes of 16,500 to 45,000 feet (5 to 13 kilometers) and are usually associated with fair weather.