This side-by-side comparison from the Suomi NPP polar-orbiting satellite shows snow-covered Eastern Europe before and after a plume of dust from the Sahara Desert blanketed the region over the weekend. In the left hand image, snow cover over Moldova and Ukraine appears bright white; in the right image, the snow has a brown and orange tint due to Saharan dust settling over the region. Occasionally, strong southwesterly winds transport large quantities of sand from the Sahara northward across the Mediterranean Sea into Europe. This Saharan dust event was particularly intense, with widespread media reports of orange-tinted snow at ski resorts as far as away as southeast Russia, along the Black Sea.
Although true-color images like this may appear to be photographs of Earth, they aren't. They are created by combining data from the three color channels on the VIIRS instrument sensitive to the red, green and blue (or RGB) wavelengths of light into one composite image. In addition, data from several other channels are often also included to cancel out or correct atmospheric interference that may blur parts of the image.