A chimpanzee feeding a leopard cub at Southam Park Zoo, Warwickshire. (Photo by Ian Tyas/Keystone Features/Getty Images). 1971

Clutching a large paper bag and shading his eyes as he peers ahead, comic actor of the silent screen, Buster Keaton (1885–1966) arriving at Paris airport. (Photo by Keystone/Getty Images). 1st August 1947

Sparks are thrown as an employee grinds the edges of a ski at the plant of Swiss ski manufacturer Stoeckli in Malters, Switzerland November 25, 2015. Stoeckli plans to produce some 1,000 pair of skis per year of a special edition for Swiss watch manufacturer TAG Heuer, a brand of LVMH Group. (Photo by Arnd Wiegmann/Reuters)

A salsa dancer performs in the “Salsodromo” parade, which marks the start of the Fair of Cali, Colombia, December 25, 2015. Picture taken December 25, 2015. (Photo by Jaime Saldarriaga/Reuters)

Nepalese Mahuts with their elephant participate in elephant picnic as a part of the12th Chitawan Elephant Festival at Sauhara, Chitawan, some 154 kilometer from the capital of Kathmandu, Nepal, 28 December 2015. More than 80 elephant with their Mahuts joined the elephant picnic. The five-day festival began on 26 December to spread awareness about wildlife and promote tourism. (Photo by Hemanta Shrestha/EPA)

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)

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)