Amundsen-Scott South Pole Station experiences months of darkness. The sun dips below the horizon on March 21, after which follows several weeks of twilight before complete darkness results. Photo taken on June 25, 2009. (National Science Foundation/Jeremy Johnson)

Children watch and react as a T-Rex moves and growls in an inter-active display at Field Station Dinosaurs in Secaucus, N.J on May 25, 2012. There will be 31 types of life-sized dinosaurs displayed at the Jurassic expedition that opens Saturday, May 26. (Photo by Mel Evans/Associated Press)

Iranian worshippers chant slogans during a protest after their Friday prayer, as part of widespread anger across the Muslim world about a film ridiculing Islam's Prophet Muhammad on September 14, 2012. (Photo by Vahid Salemi/Associated Press)

A four-month-old snow fox cub named “Vesna” (“Spring”) leaps next to a Zoo employee at the Royev Ruchey Zoo in Krasnoyarsk, Russia, on August 6, 2013. (Photo by Ilya Naymushin/Reuters)

Hundreds of festive, adorable canines and their owners took part in the annual “A Very Corgi Howloween” costume walk Saturday, October 25, 2014, at Green Lake in Seattle, Wash. The walk was put on by the Seattle-local “Corgi's R Us” MeetUp group. (Photo by Jordan Stead/AP Photo/Seattlepi.com)

History enthusiasts dressed as soldiers fight during the re-enactment of Napoleon's famous battle of Austerlitz near the southern Moravian town of Slavkov u Brna November 29, 2014. Hundreds of history enthusiasts took part in the re-enactment of the battle to mark its 209th anniversary. (Photo by David W. Cerny/Reuters)

Volunteers transport an inflated sphere into a canoe to be lowered in MacArthur Park Lake during the installation of Portraits of Hope's exhibition “Spheres at MacArthur Park” in Los Angeles, California August 21, 2015. The installation will feature about 3,000 inflatable hand-painted spheres. (Photo by Mario Anzuoni/Reuters)

Children attend a war safety awareness class conducted by civil defence members, in the rebel-controlled area of Maaret al-Numan town in Idlib province, Syria May 14, 2016. (Photo by Khalil Ashawi/Reuters)