A curious leopard cub toys with a camera at MalaMala Game Reserve in Mpumalanga Province, South Africa. (Photo by Barcroft Media)

The giant mural titled “Under the Hand” by Maclaim Crew is visible on a building facade in Kreuzberg district on June 26, 2014 in Berlin, Germany. Berlin, with its long tradition of counter-culture, has become a mecca for street art of all dimensions and messages. (Photo by Sean Gallup/Getty Images)

An airplane passes the moon as it makes its approach to Philadelphia International Airport, Sunday, September 7, 2014, in Philadelphia. (Photo by Matt Rourke/AP Photo)

A dog rides a wave while competing during the 5th Annual Surf Dog competition at Huntington Beach, California, on September 29, 2013. (Photo by Frederic J. Brown/AFP Photo)

Two guards perform an execution in China, one holding the gun, the other holding a mask over the victim's face. (Photo by General Photographic Agency/Getty Images). Circa 1925

The attendants of the Sumptha Raja, Agra Durbar. (Photo by Hulton Archive/Getty Images). 1873

Marianne Brauns jumping a breakwater on the beach, wearing a structured blue swimsuit with white trim. (Photo by Carl Sutton/Hulton Archive/Getty Images). Circa 1950

A visiitor bungee jumps during an outdoor festival to celebrate German Unity Day on the 21st anniversary of German reunification on October 3, 2011 in Berlin, Germany. German Unity Day is a national holiday and marks the day West Germany and East Germany were reunited in 1990 following the collapse of the Iron Curtain. (Photo by Adam Berry/Getty Images)