Atmospheric Effects Gases such as carbon dioxide, water vapor, oxygen, ozone interfere with electromagnetic energy absorption and reflection. The figure below illustrates the effects of interaction behaviors with different matter.   Source: http://rst.gsfc.nasa.gov/ The illustrations below depict the four types of interaction between electromagnetic radiation and matter. Source: http://rst.gsfc.nasa.gov/ Atmospheric scattering (illustrated at bottom left of figure above) of light results in haze and reduced image sharpness.   There are 3 types of atmospheric scattering that depend on the wavelength of the electromagnetic radiation (EMR) and the size of the atmospheric particle the radiation is interacting with. Rayleigh scattering: the diameter of particles << wavelength of EMR preferentially scatters EMR at the wavelength of blue light...this is what makes Earth skies appear blue Mie scatter: diameter of particles = wavelength of EMR caused primarily by water vapor, fumes, smoke, and dust results in red/orange appearance of evening Earth skies or when forest fires or volcanoes are putting particulates and smoke into the atmosphere Non-selective scatter: diameter of particles >> wavelength of EMR all wavelengths of light scatter equally caused by dust, clouds, and fog BLAZING RED SUNSET CAUSED BY MIE SCATTERING OF EMR YELLOW-ORANGE TINT TO SKY CAUSED BY FOREST FIRE SMOKE Source: www.acclaimimages.com/_gallery/