For those who missed it, Feb. 19 brought a super snow moon, the biggest and brightest supermoon of the year. Social media and national news sites lit up with spectacular photos of the event, with an unusually large full moon rising above the horizon.
Although reminding us of the beauty of the night sky, similar events can also highlight the spread of light pollution, which dramatically limits celestial views and deprives us of those awe-inspiring encounters with the night sky.
Light pollution has raised increasing alarm in recent years. Research estimates that 99 percent of Americans live within its glare, and that 80 percent of us no longer experience the once-common view of the Milky Way. Health experts point out that excessive exposure to artificial lighting also disrupts the human circadian rhythm, increasing our susceptibility to obesity, depression, dementia, cancer, and other health problems.
Preserving natural darkness is about much more than human health and experience. Affecting plants to wildlife, dark nights are vital for sleep, migration, hunting, feeding, reproduction, and much more.
Our exposure to artificial lighting is increasing, but so is awareness of these issues, and a number of organizations are working to preserve existing areas of natural darkness and reduce the spread of light pollution.
Founded in 1988 by a small group of professional and amateur astronomers, the nonprofit International Dark-Sky Association has more than 60 volunteer-led chapters worldwide that work to protect naturally dark sky. The association offers a certification called International Dark-Sky Park, where land managers pledge to eliminate unnecessary lighting and educate visitors about the values of natural darkness. Across the U.S., more than 40 parks have been certified, along with the Central Idaho Dark Sky Reserve, which spans more than 1,400 square miles of remote national forest.
The improvements benefit park visitors but also residents of the broader region, who gain a new tool for ensuring their skies remain unpolluted by light. Additionally, local economies experience a boost through the growing astrotourism trend, which attracts new visitors and encourages more overnight stays.
While investment and technology are important to reducing light pollution, “education is one of our most powerful tools,” says Amanda Gormley, communications director for the International Dark-Sky Association. “We have chapters all over the world, and they each work to raise awareness about dark sky.”
For example, the Texas Night Sky Festival, a two-day biennial event, brought out thousands of people to the city of Dripping Springs last year. In addition to offering food and music, the festival featured information booths, solar viewing, and art contests celebrating the area’s night sky.
Partnered with local planetariums, some chapters host “star parties” throughout the year, where professional and amateur astronomers share views through their telescopes. Other chapters offer full-moon hikes or speaker programs, all aiming to reconnect people with local views of the heavens, an essential first step in broader efforts to preserve dark sky in an increasingly well-lit world.
That first step is important but perhaps not significant enough to darken skies as quickly as artificial light is polluting them. As Dark-Sky focuses more on parks and protected lands, denser and more-populated areas grow bigger and brighter.
To that end, the association reaches out to local governments, providing a model lighting ordinance for managing or reducing artificial light. The model draws from examples of lighting ordinances that already exist in at least 18 states and thousands of U.S. cities. Thanks in part to the association’s recommendations, Tucson recently reduced its sky glare by 7 percent while replacing thousands of older streetlights with newer LED lights.
Some energy-efficient lights are harmful to human health and dark skies. With more communities transitioning to LED lighting, the association also offers a practical guide to steer planners toward safe light-shielding products.
Artificial light is pervasive in our lives. Sometimes, as with climate change, an issue tied so closely to our modern comfort can seem impossible to solve. But a closer look shows a field popping with new ideas. It’s a little like the stars that appear when we find a moment to enjoy views of a naturally dark sky.
Tim Lydon has worked on public lands issues for many years and is a founding member of the Prince William Sound Stewardship Foundation. His writing has appeared in Hakai Magazine, The Revelator, The Hill, Terrain.org, and elsewhere.