A Syrian refugee girl cries as she walks through a rainstorm towards Greece's border with Macedonia, near the Greek village of Idomeni, September 10, 2015. Most of the people flooding into Europe are refes fleeing violence and persecution in their home countries who have a legal right to seek asylum, the United Nations said on Tuesday. (Photo by Yannis Behrakis/Reuters)

Olaf Niess catches swans on the river Alster near the town hall in Hamburg, Germany, 17 November 2015. The Alster swans are moving to their ice-free winter quarters on the Eppendorf Muehlenteich millpond until spring. (Photo by Bodo Marks/EPA)

Firework display from the top of the Sky Tower to welcome the New Year on January 1, 2015 in Auckland, New Zealand. (Photo by Dave Rowland/Getty Images)

A devotee holds incense sticks while celebrating the Sindoor Jatra Festival on April 15, 2015 in Thimi, Nepal. Sindoor Jatra Festival is celebrated each year in Thimi, on the outskirts of Kathmandu, to welcome the Nepali New Year and celebrate the coming of spring. During the Festival, devotees are smeared with vermillion powder and 30 chariots containing the images of several gods and goddesses are carrying by the devotees around the town, while others sing, dance and play musical instruments. (Photo by Omar Havana/Getty Images)

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)

German flying ace Baron Manfred von Richthofen (1892–1918) also known as The Red Baron with his dog Moritz, circa 1916.

Yuccas catch fire as the Powerhouse fire makes a fast run toward Lake Hughes, south of Lake Hughes, California, on June 1, 2013. The 19,500-acre wildfire destroyed numerous homes overnight. (Photo by David McNew/Getty Images)

A man pushes her daughter on a cart as they shop at a market in Seoul, South Korea, July 26, 2016. (Photo by Kim Hong-Ji/Reuters)