A sun halo is a circle that encircles the sun. It occurs when the sun's tilt toward high-level clouds shines sunlight onto the clouds' ice crystals. High clouds are made up of thousands of small ice crystals. The light is refracted by the ice crystals, forming a prism and resulting in the rainbow colors from each. The effect can be seen from a great distance (up to 100 miles) because the sun is so large compared to the crystal size.
The sun becomes visible after sunset or before sunrise. When this happens there is no moon to interfere and so you see its entire disk as it passes across the sky.
You may have seen pictures of sun halos on websites or in magazines. But they aren't real! Sun halos are images created by photographers who know how to manipulate the light with lenses and photoshop software. This article explains why people make up stories about seeing the stars within a sun halo and gives some examples of these myths.
The refraction, reflection, and dispersion of light through ice particles contained within thin, wispy, high-altitude cirrus or cirrostratus clouds causes a sun halo. Light is twisted at a 22 degree angle as it travels through these hexagon-shaped ice crystals, forming a circular halo around the Sun. The effect is most visible when you view the Sun from a high altitude (at least 10,000 feet), in clear air with little dust or other aerosols present to scatter light.
When observing the sun with the naked eye or using a solar filter, the human eye is very sensitive to changes in brightness, especially if they occur rapidly. So when viewing the sun with the unaided eye, it is necessary to be aware of this natural tendency and try not to blink for several minutes at a time. This would certainly be uncomfortable after only a few moments, but if this behavior is repeated on and off for an entire hour, it can result in severe eyestrain and possibly blindness.
The sun halo is created as light passes through the clouds to reach your eye. As it does so, it is scattered by the water droplets inside the cloud and bent away from its original path toward the Sun. Thus, part of the light is reflected back into space while another part reaches your eye as a faint circle around the Sun.
The color of the sun halo varies depending on the type of cloud that creates it.
The Sun Halo, also known as the "22-degree halo," is an optical phenomena caused by sunlight refracted by millions of hexagonal ice crystals floating in the sky. It assumes the shape of a ring with a radius of around 22 degrees that revolves around the sun or moon. The crystal particles are usually frozen raindrops that accumulate during a cold night when there is no precipitation. They then melt during the day when temperatures rise, causing them to evaporate again.
The Sun Halo appears as a bright circle around a star or planet when clouds block its light from reaching the earth. As the frozen raindrops evaporate, they leave a visible trail in the sky called a cirrus cloud. This is how astronomers know that storms are approaching; you can see lines of snow falling from cirrus clouds.
Solar halos can be seen anywhere on Earth where it is dark enough for stars to shine brightly, but not completely obscured by clouds. Due to their proximity to the Earth, planets like Venus and Mars often feature large, thin rings of dust that reflect light from their surfaces. These rings are not visible in daylight because they are blocked by the planet's atmosphere.
Planets like Jupiter and Saturn have strong magnetic fields that trap electrons around them. These electrons then collide with other atoms creating a rainbow of colors in the clouds above these planets.
A halo is a ring of light that develops around the sun or moon when the light from the sun or moon refracts off ice crystals in a thin veil of cirrus clouds. The halo is typically perceived as a dazzling, white ring, although it can also be colored. Halos are often seen around the moon but are much more common around the sun because water droplets within the atmosphere scatter blue and red wavelengths of light but not all colors. The result is a yellow-white circle with dark borders.
Halos can be either internal or external. An internal halo forms within the body of the moon or sun, while an external halo surrounds them. External halos are usually caused by clouds, while internal halos can occur without any visible cause.
The color of a halo varies depending on what part of the spectrum is being scattered. Blue wavelengths are most strongly scattered by water droplets, so they form a white ring around the moon or sun. Red wavelengths are less affected by scattering, so they remain behind to paint the sky as twilight fades.
Halo effects can be seen with the unaided eye during a total solar eclipse when Earth's atmosphere acts as a mirror to bend light from the sun around our planet. During a partial eclipse, where only part of the sun is obscured, observers see only a portion of the complete solar halo.