DarkSky International

DarkSky International, formerly the International Dark-Sky Association (IDA), is a United States–based nonprofit organization incorporated in 1988 by founders David Crawford, a professional astronomer, and Tim Hunter, a physician and amateur astronomer. The mission of DarkSky is "to preserve and protect the night time environment and our heritage of dark skies through quality outdoor lighting."

Light pollution is the result of outdoor lighting that is not properly shielded, allowing light shine into the eyes and night sky. Direct light that shines into the eyes is called glare, and light directed into the night sky above the horizon causes skyglow. Lighting can also cause light trespass when it enters areas where unwanted (e.g. a neighbor's yard and windows). DarkSky is the first and currently the largest organization in the dark-sky movement.