International Dark Sky Week

International Dark Sky Week

International Dark Sky Week, a concept originally proposed in 2003 by a high school student from Midlothian, Virginia, named Jennifer Barlow, is an initiative designed to raise awareness of light pollution. Sponsored by the International Dark-Sky Association (IDA), the only non-profit organization dedicated to night sky preservation, Dark Sky Week has become an international event and a cornerstone of Global Astronomy Month.


The primary goals of Dark Sky Week are to raise awareness about the negative effects of light pollution and to inspire people to celebrate the night sky, taking action to protect it. Light pollution, the unnatural brightening of the night sky caused by man-made light sources, increases 4% per year. Most prominent in densely populated, urban areas, light pollution accounts for our inability to see many stars while in a city; the further out into the country you go, the more stars and other astronomical objects are visible in the night sky.

On one hand, our artificial light sources have enabled tremendous advances in human civilization; on the other hand, the unwanted side effects of light pollution have serious consequences. In addition to inhibiting astronomical research and disconnecting us from the wondrous night sky that inspired our ancestors, light pollution also disrupts our natural circadian rhythms (our internal body clocks, set by the presence and absence of daylight, that let us know when it’s time to sleep and time to wake up), as well as wildlife ecosystems.

Fortunately, there are specific measures that prevent light pollution by reducing excessive light and shielding misdirected light from projecting into the night sky. In the interest of night sky preservation, as well as of safety, security, and aesthetics - the primary purposes of outdoor lighting - a little forethought goes a long way.

Save energy and avoid unnecessary and excessive outdoor lighting with the use of lighting controls-timers, dimmers, and motion sensors that ensure lights are on only when needed.



Properly shielded outdoor fixtures concentrate light where it’s needed, projecting out and towards the ground, not up into the sky. While California is the only state that mandates the use of Dark Sky rated fixtures by law, it’s a good idea to use them no matter where you live.