Park Authority

Fairfax County, Virginia

CONTACT INFORMATION: Open during regular business hours 8 a.m. - 4:30 p.m., Monday - Friday

703-324-8700
TTY 711

12055 Government Center Pkwy.
Fairfax, Virginia 22035

Jai Cole,
Executive Director

Department Resources


Dark Skies

Dark Skies Light to Protect the Night

Dark skies are the historic and natural state of nature. Over time humans have increased the amount of light shining into the sky all night long. This disruption of excessive light has robbed us of our stars and endangered the nature around us. We can have dark skies again if we can learn to control light pollution with responsible outdoor lighting practices.

Light Pollution Components

Skyglow

Skyglow is the brightening of the night sky over inhabited areas.

skyglow

Glare

Glare is excessive brightening that causes visual discomfort.

glare

Light Trespass

Light trespass is light falling where it is not intended or needed.

light trespass

Why is Dark Sky Conservation Important?

light pollution across the world; bright light shining on a wolf, a turtle, a frog, and some birds

Economic Benefits

Proper night sky friendly lighting lowers CO2 emission and lowers energy costs. Dark sky practices prevent the wasted energy of light shining where it is not needed or wanted.

Human Health and Sleep Benefits

Artificial light at night has multiple negative human health impacts: blue light at night disrupts a human’s circadian rhythm and suppresses melatonin secretion.

Safety Benefits

Bright light does not increase safety! Rather, the placement, color and shielding of light needs to be done wisely to ensure safe perception of space.

Environmental Benefits

Dark skies are vital for keeping plants and animals safe in their natural environment. Nocturnal animals are adapted to the darkness and lose their way in artificial light. Nocturnal pollinators avoid lights and those that don’t get eaten. Plants use light as a calendar so artificial light at night causes plants to leaf when they should flower and reduces crop production. Some varieties of strawberry need the dark to produce fruit.

 

Dark Sky Friendly Outdoor Lighting Principles

a list of dark sky friendly outdoor lighting principles

Click image to download accessible PDF.

 

a depiction of dark sky friendly outdoor lighting with emphasis on shielding, color temperature, intensity, and timing

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