French firemen wearing chemical protective suits take part in a mock chemical attack exercise at the Geoffroy Guichard stadium in Saint-Etienne, France, April 4, 2016 in preparation of security measures for the UEFA 2016 European Championship. (Photo by Robert Pratta/Reuters)

Women wearing prosthetic legs participate in a public photo session at the Hasselblad and Profoto booth, during the CP+ camera and imaging equipment trade fair in Yokohama south of Tokyo, February 14, 2015. Japanese prosthetist Fumio Usui inspired the event after collaborating with photographer Takao Ochi in the book project “Amputee Venus” that portrays 11 Japanese women with artificial legs, local media reported. (Photo by Thomas Peter/Reuters)

Hundreds of Nigerians celebrate at an intersection in the flashpoint northern city of Kaduna on March 31, 2015 the victory of main opposition All Progressives Congress (APC) presidential candidate Mohammadu Buhari. (Photo by Nichole Sobecki/AFP Photo)

A visitor holds up her toy bunny to the aquarium glass in front of Aurora the Russian polar bear at the Sao Paulo Aquarium in Sao Paulo, Brazil, Thursday, April 16, 2015. (Photo by Andre Penner/AP Photo)

NASA handout photographs from the various Apollo missions are shown in this combination photograph. The photographs are some of more than 12,000 from NASA's archives recently aggregated on the Project Apollo Archive Flickr account. (Top L) David R. Scott, command module pilot, stands in the open hatch of the Command Module during the Apollo 9 mission March 6, 1969. (Top centre) Edwin "Buzz" Aldrin Jr.walks on the surface of the moon during the Apollo 11 mission July 20, 1969. (Top R) Neil Armstrong, Apollo 11 commander, is pictured inside the Lunar Module during the Apollo 11 mission July 20, 1969. (Bottom L) Alan Bean holds a container filled with lunar soil collected during the Apollo 12 mission November 19, 1969. (Bottom centre) Scientist-astronaut Harrison Schmitt rides in the Lunar Roving Vehicle during the Apollo 17 mission December 13, 1972. (Bottom R) Harrison Schmitt stands next to a huge, split boulder during the Apollo 17 mission December 13, 1972. (Photo by Reuters/NASA)

A paddler races in a giant pumpkin during the annual regatta on Lake Pisiquid in Windsor, Nova Scotia, Sunday, October 11, 2015. Participants hollow out the massive gourds and pilot them across the 500 meter course. (Photo by Andrew Vaughan/The Canadian Press via AP Photo)

Members of ASC Tornados, the motorcycle display team of the Indian army, lie in a row on the ground as another performs a stunt by jumping over them during the 225th anniversary celebrations of Army Service Corps in Bangalore, India, Tuesday, December 8, 2015. The Army Service Corps which was established in 1790 is an arm of the Indian Army which handles its logistic support function. (Photo by Aijaz Rahi/AP Photo)

Participants prepare backstage before the 5th “Strongo Cup” open amateur bodybuilding tournament at the State Opera and Ballet Theatre in Russia's Siberian city of Krasnoyarsk, November 1, 2014. Participants from all over Russia took part in the tournament competing in bodybuilding, body fitness and bikini fitness disciplines. (Photo by Ilya Naymushin/Reuters)