Milky Way, a faded memory to one-third of humanity

The luminous glow of light pollution prevents one third of humanity and 80 percent of Americans from seeing the Milky Way, the brilliant river of stars that has dominated the night sky and human imaginations since time immemorial, according to a new global atlas of light pollution produced by Italian and American scientists.

Light pollution is one of the most pervasive forms of environmental alteration. In most developed countries, the ubiquitous presence of artificial lights creates a luminous fog that swamps the stars and constellations of the night sky.

"We've got whole generations of people in the United States who have never seen the Milky Way," said Chris Elvidge, a scientist with NOAA's National Centers for Environmental Information in Boulder, Colorado, adding "It's a big part of our connection to the cosmos and it's been lost."

Using high-resolution satellite data and precision sky brightness measurements, their study produced the most accurate assessment yet of the global impact of light pollution.

"I hope that this atlas will finally open the eyes of people to light pollution," said lead author Fabio Falchi from the Light Pollution Science and Technology Institute in Italy.

"In the U.S., some of our national parks are just about the last refuge of darkness - places like Yellowstone and the desert southwest," said co-author Dan Duriscoe of the National Park Service. "We're lucky to have a lot of public land that provides a buffer from large cities."

Light pollution does more than rob humans of the opportunity to ponder the night sky. Unnatural light can confuse or expose wildlife like insects, birds and sea turtles, with often fatal consequences.

Fortunately, light pollution can be controlled by shielding lights to limit shine to the immediate area, reducing lighting to the minimum amount needed -- or by simply turning them off.

The study appears in the journal Science Advances.