Skyglow Swallows the Milky Way for Over a Third of Humanity
Artificial skyglow now hides the Milky Way from more than a third of humanity, not because the galaxy has dimmed but because urban lighting brightens the night sky. A 2016 atlas using satellite radiance and 35,000 ground observations estimated that about 83% of people live under light-polluted skies, with the Milky Way’s visibility falling below a defined threshold under typical clear-sky conditions. Visibility varies by location, weather, and dark-adaptation. Skyglow results from scattered artificial light in the atmosphere, distinct from glare or light trespass. Studies show sky brightness has been rising in many places (7–10% per year in some datasets), and while LEDs offer efficiency, rebound effects and blue-rich light can worsen the problem. Solutions call for targeted, downward-facing, low-level, warm-colored lighting with controls, recognizing that the Milky Way remains—it’s the brightened air between us and it that has changed.
