(WFLA) — Stargazers in parts of Europe were stunned by an unusual sight on Monday evening: a large, glowing blue spiral ... the setting sun and appearing to spin in the sky.

T he sky isn't just blue by chance ... to pass through a larger part of the atmosphere when the sun is lower on the horizon. Red, orange and yellow have longer wavelengths, which means, in ...

Why is the sky blue in colour ... This is why we often see beautiful red and orange hues during the rising and setting sun. Rayleigh scattering, however, is not the only factor responsible ...