Sunsets in Chile

Morning civil twilight begins when the geometric center of the sun is 6 degrees below the horizon and ends at sunrise. 

While at sunset, the light must pass through more atmosphere, scattering violets and blues, leaving yellows, oranges, and reds. Aerosols suspended in the air scatter sunlight into a band of colors. When there are more aerosols or smog, more sunlight is scattered, resulting in purple or pink sunsets.