Post written by Rosalia Coz, OEEC Summer 2024 Intern

The Dark Sky conservation movement is committed to reducing the light pollution that harms the natural world and hinders our enjoyment of the nighttime sky. Read on to learn more about the problem and how sky-friendly lighting can also help you sleep better, save energy and protect plant and animal life.

What is light pollution?

Light pollution is the excessive use of outdoor artificial light and is generally recognized as a form of environmental pollution. Light pollution has many symptoms including “sky glow” which is the unnatural brightening of the night sky. It can have measurable effects on human health, wildlife, public safety, and energy security.

Artificial light at night (ALAN) is the primary driver of light pollution. This includes outdoor lights that emit white light upward or sideways— including streetlights, electronic advertisements or billboards, sports lighting, and more.

What is dark sky lighting?

Dark sky lighting is a solution to light pollution, without eliminating outdoor ALAN altogether. According to Saving Our Stars, dark sky lighting is a way of lighting that helps keep the sky dark by fully shielding the light bulb on the top and sides so that the light is directed down rather than to the sides and up into the sky. It is amber in color rather than blue, green, or white. It is dimmed and no brighter than necessary, only used when needed, and often operates on timers or motion detectors.

What are the benefits of dark sky lighting?

Dark sky lighting is important for five main reasons:

1. Safety: It can increase pedestrian and driver safety by reducing dangerous glare, significantly impacting the ability to see clearly.
2. Health: Sleep is an important aspect of our health, as good sleep helps our immune system, heart and cognitive and mental health. Excessive light at night can disrupt our natural circadian rhythm, interfering with good sleep. Dark sky lighting can reduce the negative impacts of ALAN on our sleep by limiting exposure to bright night light.
3. Wildlife: Nighttime is important to the Earth’s ecosystem, and thus dark skies are essential to preserving the natural processes of surrounding wildlife. ALAN can disrupt breeding, migration, and behavior patterns. 
4. Rest: Dark sky lighting utilizes warm colors that resemble sunsets and promote relaxation. Additionally, darkness promotes melatonin production, a natural sleep aid, while bright lights slow melatonin production. 
5. Our planet: There are significant amounts of wasted energy in traditional outdoor lighting, and dark sky lighting helps to minimize that waste by only using energy for lighting the necessary time, amount, and task needed.

How can you help?

Dark sky lighting and light pollution-reducing strategies can be used at home! Some ways to implement dark sky lighting into your home include:

• Review Fairfax County’s outdoor lighting ordinance
• Utilize motion sensors and timers on outdoor lighting
• Avoid bright white, blue, green, or red LED lights; warm colored LEDs are better
• Use lighting fixtures that cover the top and sides of the light bulb
• Reserve a Light Pollution Monitoring Kit at your favorite Fairfax County Public Library branch
• Turn off unnecessary indoor lighting at night that can be seen through windows and doors 
• Look for IDA Dark Sky Approved lighting
• Get involved by joining a group like the Northern Virginia chapter of DarkSky International

Learn More

Visit Fairfax County’s Dark Skies topic page for more information and resources. 

Attend the “Save the Night!” event on November 17 at the Vienna Community Center. Visit Dark Sky NOVA's website to learn more about this family-friendly afternoon dedicated to exploring the effects of light pollution and how it impacts our life and health.