Light pollution

Light pollution is the glow of the sky caused by an artificial light scattered by gases, dust and aerosols in the atmosphere, associated with poor quality outdoor lighting. Poorly designed devices turn some part of the light in the sky instead of to the ground. The result is the flare (so called tresspass), blinding (glare) and wasting energy.

Photo provided by NASA on Visible Earth (http://visibleearth.nasa.gov/). [Data courtesy Marc Imhoff of NASA GSFC and Christopher Elvidge of NOAA NGDC. Image by Craig Mayhew and Robert Simmon, NASA GSFC]