A leopard seal feeds Paul Nicklen a penguin. (Photo by Paul Nicklen/National Geographic). Antarctic Peninsula, 2011

A indigenous man from the Tabajara tribe is seen in Tocantins river before the I World Games for Indigenous People in Palmas, Brazil, October 21, 2015. (Photo by Ueslei Marcelino/Reuters)

Bikers passes along the High Street on March 18, 2012 in Royal Wootton Bassett, England. The ride, in its third and final year and involving thousands of bikers started at Hullavington airfield and aims to honour the people of Royal Wootton Bassett and to raise money for the Afghan Heroes charity. (Photo by Matt Cardy/Getty Images)

NASA space shuttle Atlantis in Earth orbit is seen during a Rendezvous Pitch Maneuver, or back flip to enable space station crew members to take high resolution digital pictures of the shuttle's heat shield before docking for the last time with the International Space Station July 10, 2011 in space. Atlantis has embarked on a 12-day mission to the International Space Station where it will deliver the Raffaello multi-purpose logistics module packed with supplies and spare parts. This will be the final launch of the space shuttle program, which began on April 12, 1981 with the launch of Colombia. (Photo by NASA via Getty Images)

Factory landlord Lawrence Taylor (L), portraying a Colour Sergeant from the King's Royal Rifle Corps, part of the Rifles Living History Society, performs a drill with Connor Young (R) of the Queen's Own Royal West Kent Regiment Living History Group as they recreate the life of a First World War soldier at the Eden Valley Museum in Edenbridge in southeast England May 10, 2014. Lawrence has always had an interest in military history and specifically “The Rifles” – his veteran father's WWII regiment. When he became a re-enactor he chose not to re-enact WWII as many of the veterans are still alive, and he felt uncomfortable as he remembers his father would have flashbacks and nightmares about the war. United by a fascination with military history and a fondness for dressing up, groups such as the Rifles Living History Society and the Queen's Own Royal West Kent Regiment Living History Group get together to recreate aspects of life during the First World War. Reuters photographer Luke MacGregor photographed members of the groups, both as they took part in living history events and at their day jobs. (Photo by Luke MacGregor/Reuters)

A model showcases designs on the catwalk during Beijing Institute of Fashion Technology and Taiwan Shin Chien University Graduates Collection show of China Fashion Week A/W 2011 on March 25, 2011 in Beijing, China. (Photo by Feng Li/Getty Images)

Dr. P.A. Smithe was sent by the American Red Cross as a doctor and surgeon to work at a hospital in Vienna. He sailed to Europe in December 1915 and returned home in August 1916, according to his daughter, who donated his images to the National World War I Museum. Photo: Turkish army, including cavalry, infantry and artillery. (Photo by Dr. P.A. Smithe/National World War I Museum, Kansas City, Mo.)

Bride Fan Huixiang (front R), a 25-year-old cancer patient, receives flowers from nurses on her bed before her wedding ceremony at a hospital in Zhengzhou, Henan province November 17, 2014. Fan was diagnosed with late stage adenocarcinoma, a type of cancerous tumor, at her thoracic vertebra this June. She and her 24-year-old husband Yu Haining held their wedding ceremony at the hospital on Monday after five years of relationship, local media reported. (Photo by Reuters/China Daily)