The scientists said that around 30% of humans can no longer see the Milky Way, even on the clearest night. They added that the levels of light pollution in some countries have now touched such high that people never experience a true night sky, because an artificial twilight's glow masks it perpetually.
"Most of the world is affected by this problem, and humanity has enveloped our planet in a luminous fog that prevents most of Earth's population from having the opportunity to view our galaxy," the researchers behind the effort wrote in a study published Friday in the journal Science Advances.
Over a decade ago, the researchers had created the first world atlas of artificial night-sky brightness. The latest version, however, has more sophisticated tools, such as imaging data from a high-resolution satellite operated by the National Oceanic and Atmospheric Administration. The result is a detailed global map of light pollution.
"As light hits molecules and particles in the atmosphere, it gets scattered, " said Chris Elvidge, a co-author and a physical scientist for NOAA. "It's light coming from the sky down toward us that blocks our ability to see the stars."
The researchers said that Singapore is the most light-polluted country in the world as here the entire population lives under skies so bright that the human eye never fully adapts to night vision. Citizens of other countries such as Kuwait, Saudi Arabia, South Korea, Israel and Argentina have almost entirely obstructed views of the sky at night.