  Artificial lights raise night sky luminance, creating the most visible effect
of light pollution-artificial skyglow. Despite the increasing interest among
scientists in fields such as ecology, astronomy, health care, and land-use
planning, light pollution lacks a current quantification of its magnitude on a
global scale. To overcome this, we present the world atlas of artificial sky
luminance, computed with our light pollution propagation software using new
high-resolution satellite data and new precision sky brightness measurements.
This atlas shows that more than 80% of the world and more than 99% of the U.S.
and European populations live under light-polluted skies. The Milky Way is
hidden from more than one-third of humanity, including 60% of Europeans and
nearly 80% of North Americans. Moreover, 23% of the world's land surfaces
between 75{\deg}N and 60{\deg}S, 88% of Europe, and almost half of the United
States experience light-polluted nights.
