What do you get when you mix clean, white snow with dust from the Sahara Desert? You get dirty, orange snow! Once every five years or so this happens in Europe. Dust from Saharan sand storms is lifted into the upper layers of the atmosphere, where it spreads out and drifts across the Mediterranean. It then mixes with rain and snow and falls to the ground.

Figure 1: Photo of orange snow at a ski resort near Sochi, Russia.

For more pictures and information, see articles from Time, the BBC, and USA Today.