Organized since 2009 by The World at Night (TWAN), this year's selected theme was "Dark Skies Importance." The submitted photos were judged in two categories: "Beauty of The Night Sky" and "Against The Lights." The images were taken in 57 countries and those selected were those most effective in demonstrating how important the starry sky is and how bad the problem of light pollution has become.
Today, most city skies are virtually devoid of stars. According to to TWAN, light pollution (excessive light that scatters to the sky instead of illuminating the ground) is not only a major waste of energy, it also obscures the stars, disrupts ecosystems and has adverse health effects.
Above: The first prize in "Beauty of the Night Sky" category goes to Stephanie Ye from China for "The Tail of Aurora" captured in March 2015 in northern Norway.