During a Total Eclipse
One of the most amazing examples of the Venus Belt, or at least a similar effect as the Venus Belt is during the time of a total solar eclipse. What occurs to cause this effect is when the light from the sun is blocked by the moon, sunlight is still able to shine past the moon which allowing some light to reach the earth.
The resulting colors are from a phenomenon called scattering which occurs when molecules and small particles in the atmosphere change the direction of light rays, causing them to scatter.
Total Solar Eclipse, Burris, Wyoming
How Scattering Affects Light Rays
This scattering affects the amount of light coming from the sky, but the amount of scattering of the different colors of light is determined by both the wavelength of the light and by the amount and size of the particles.
The short-wavelength blue and violet rays are scattered by molecules in the air much more so than other colors of the spectrum. This is why blue and violet light reaches our eyes from all directions on a clear sunny day. However, it is because we can not see violet very well that the sky appears to us to be blue.
Venus Belt during Solar Eclipse
Increased Atmosphere, Increased Scattering
When the rays of sunlight pass through more atmosphere, such as during the suntouch and during a total eclipse, the light rays must also pass through more molecules. The first light rays to be scattered are the light rays with the shorter wavelengths, the blue and violet rays. Also, if the path the light travels through the atmosphere is long enough, all of the blue and violet rays will be scattered. What remains to reach the observer′s eye are those rays with longer wavelengths, the orange, red and yellow light rays.
Since red light rays have the longest wavelength, this is why the sun is red when it is at suntouch, a time when the extremely long path through the atmosphere blocks all other light rays.