A woman dressed as the Star Trek character “Leeta” (C) and man dressed as “Rom” (2R) arrive to attend the “Destination Star Trek London” convention at the ExCeL centre on October 19, 2012 in London, England. The three-day convention, which opened to the general public today, will be attended by all five actors who played captains throughout the 46-year-old series. (Photo by Oli Scarff)

A Republican farmer defending a farm on the outskirts of Irun against Nationalist forces during the Spanish Civil War, 6th September 1936. A comrade lies dead by his side. (Photo by Keystone/Hulton Archive/Getty Images)

A German Air Force Officer sits astride a dead boar outside a house where he is stationed near the Western Front, in this 1918 handout picture. This picture is part of a previously unpublished set of World War One (WWI) images from a private collection. The pictures offer an unusual view of varied and contrasting aspects of the conflict, from high tech artillery to mobile pigeon lofts, and from officers partying in their headquarters to the grim reality of life and death in the trenches. The year 2014 marks the centenary of the start of the war. (Photo by Reuters/Archive of Modern Conflict London)

Friends and relatives mourn by the coffin during the wake for Florjohn Cruz, who was killed in a police drugs buy-bust operation, in Manila, Philippines late October 20, 2016. (Photo by Damir Sagolj/Reuters)

People take a selfie at the abandoned former Soviet R12 nuclear missile launch site in Zeltini, Latvia, July 22, 2016. Hidden in the forests of Aluksne, near Latvia's north-eastern border with Russia, the remains of a former Soviet nuclear missile base are a magnet for tourists now rather than a top-secret site manned by soldiers. (Photo by Ints Kalnins/Reuters)

Photographer Han Youngsoo captured the ordinary people of Korea as the country emerged from war into an age of prosperity. Han Youngsoo: Photographs of Seoul 1956–63 is at the International Center of Photography (ICP), Jersey City, New Jersey, until June 9, 2017. Here: Seoul, Korea. (Photo by Han Youngsoo/The Guardian)

A Bosnian special forces soldier returns fire 06 April 1992 downtown Sarajevo as he and civilians come under fire from Serbian snipers. The Serb extremists were shooting from the roof of a hotel at a peace demonstration of some of 30,000 people as fighting between Bosnian and Serb fighters escalated in the capital of Bosnia- Hercegovina. (Photo by Mike Persson/AFP Photo)

An anti-government protester shouts at a police officer in downtown Caracas, Venezuela, Wednesday, May 10, 2017. Opponents of President Nicolas Maduro will attempt to march to the Supreme Court to protest its decision to gut the opposition-controlled congress of its powers, a ruling that was quickly rescinded under a barrage of international criticism but that set off weeks of political unrest that have left some three dozens killed. (Photo by Fernando Llano/AP Photo)