A man cries in a graveyard during the funeral of Nasser Ali Afglio, a young Libyan rebel killed during battle with government troops loyal to Libyan ruler Moammar Gaddafi April 19, 2011 in Misrata, Libya. The graveyard where Nasser was buried has hundreds of simple concrete graves; many dozens are those that have been killed during the last two months of fighting in the besieged town. Thousands of civilians are trapped in Misrata as fighting continues between Libyan government forces that have surrounded the city and anti-government rebels there. (Photo by Chris Hondros/Getty Images)

Nine-year-old Barry Miller appears none too impressed with the movements of an African Rock Python which is exploring his scalp. (Photo by Keystone/Getty Images). 27th August 1961

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 recruitment drive during the First World War at Trafalgar Square, London. (Photo by Central Press/Getty Images)

Participants ride horses, hold spears and wear historic armoured suits of the Middle Ages as they compete during the Saint George international knight tournament in Moscow, Russia, May 3, 2015. (Photo by Maxim Zmeyev/Reuters)

Russians play accordions as they walk near the building of the Federal Security Service (FSB, Soviet KGB successor) in Lubyanskaya Square to mark May Day in Moscow, Russia, Sunday, May 1, 2016. As in Soviet times, about one hundred thousand of cheerful workers paraded across Red Square despite a chilly rain, but instead of red flags with the Communist hammer and sickle, they waved the blue flags of the dominant Kremlin party and the Russian tricolor. (Photo by Alexander Zemlianichenko/AP Photo)

Astronaut Edward H. White II, pilot for the Gemini-Titan 4 (GT-4) spaceflight, floats in the zero-gravity of space during the third revolution of the GT-4 spacecraft on June 3, 1965. White wears a specially designed spacesuit. His face is shaded by a gold-plated visor to protect him from unfiltered rays of the sun. In his right hand he carries a Hand-Held Self-Maneuvering Unit (HHSMU) that gives him control over his movements in space. White also wears an emergency oxygen chest pack; and he carries a camera mounted on the HHSMU for taking pictures of the sky, Earth and the GT-4 spacecraft. He is secured to the spacecraft by a 25-feet umbilical line and a 23-feet tether line. Both lines are wrapped together in gold tape to form one cord. Astronaut James A. McDivitt, command pilot, remained inside the spacecraft during the extravehicular activity (EVA). Astronaut White died in the Apollo/Saturn 204 fire at Cape Kennedy on January 27, 1967. (Photo by NASA)

In this photo provided by Jean Revillard, Solar Impulse 2, a plane powered by the sun's rays and piloted by Andre Borschberg, approaches Kalaeloa Airport near Honolulu, Friday, July 3, 2015. His 120-hour voyage from Nagoya, Japan broke the record for the world's longest nonstop solo flight, his team said. (Photo by Jean Revillard/Global Newsroom via AP Photo)