In this photograph taken on June 28, 2015, a hiker in Hong Kong takes a picture of the city from a walking trail. The southern Chinese territory is crisscrossed by more than 180 miles of designated hiking trails. (Photo by Alex Ogle/AFP Photo)

A villager pours pesticide from a bucket as Mount Sinabung spews ash at Kebayaken village in Karo district, Indonesia's North Sumatra province, on December 4, 2013. The country has ordered the evacuation of 15,000 residents near the active volcano. (Photo by Roni Bintang/Reuters)

A diesel locomotive has ended up in the river Venoge on March 8, 2013 near Penthalaz, Western Switzerland. The freight locomotive derailed near Cossonez railway station with its driver slightly injured. (Photo by Fabrice Coffrini/AFP Photo)

A woman sits as she gets a tattoo on her leg during the annual Panama City Ink Fest in Panama City August 16, 2015. (Photo by Carlos Jasso/Reuters)

In this Wednesday, July 23, 2014 file photo, Omaha photographer Lane Hickenbottom photographs the night sky in a pasture near Callaway, Neb. With no moon in the sky, the Milky Way was visible to the naked eye. More than one-third of the world’s population can no longer see the Milky Way because of man-made lights, according to a scientific paper by Light Pollution Science and Technology Institute's Fabio Falchi and his team members, published on Friday, June 10, 2016. (Photo by Travis Heying/The Wichita Eagle via AP Photo)

A donkey savors warming temperatures after a long winter at the zoo in Warsaw, Poland, on Wednesday, April 8, 2015. (Photo by Czarek Sokolowski/AP Photo)

A man falls from an ox cart as he competes during an ox cart competition near U Bein bridge, in Mandalay March 22, 2015. (Photo by Soe Zeya Tun/Reuters)

Alex Plunkett, left, and Sean Hart, both of Arlington, Va., join hundreds participating in the annual International Pillow Fight Day on April 5. Massive pillow fights broke out on the Mall in Washington and in cities around the world. (Photo by Marvin Joseph/The Washington Post)