A runner in fancy dress participates in the Virgin London Marathon 2013 on April 21, 2013 in London, England. (Photo by Tom Dulat/Getty Images)

View at one of the sculptures by Swiss artist H.R. Giger during the opening of the Ars Electronica 2013 exhibition “HR Giger. The Art of Biomechanics” in Linz, Austria, 04 September 2013. (Photo by EPA/RUBRA)

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)

Participants wrestle while riding yaks during Kyrgyz national horse games and festival near the Tulpar-Kul in the Chon Alai range, some 3500 metres (11483 feet) above sea level, Osh region, Kyrgyzstan, July 25, 2015. (Photo by Vladimir Pirogov/Reuters)

A sofa floats in the polluted waters of Jacarepagua Lagoon, during a press tour in Rio de Janeiro, March 9, 2015. A press tour was organised by biologist Mario Moscatelli, to call attention to pollution on the waters of the lagoons which surround the Rio 2016 Olympic Park. (Photo by Ricardo Moraes/Reuters)

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)