A retired man (L) looks toward two girls wearing miniskirts, July 13, 1969 in Nice, France. (Photo by AFP Photo)

Two Inuit children at Point Barrow, Alaska, holding the tusks of a large walrus, probably killed for food, circa 1930. (Photo by General Photographic Agency/Getty Images)

A lone male cheetah is set upon by a pack of African wild dogs. Peter Haygarth had been following the dogs as they hunted in Zimanga Private Game Reserve in KwaZulu-Natal, South Africa. On first encountering the cheetah, the dogs were wary, but as the rest of the pack arrived, their confidence grew and they began to encircle the cat. Peter kept his focus on the cat’s face. In a few minutes the spat was over as the cheetah fled. (Behaviour: mammals category). (Photo by Peter Haygarth)

Members of the Oath Keepers and general public return fire during a simulated attack as they take part in a tactical training session in northern Idaho, U.S. October 1, 2016. In April 2015 Reuters photographer Jim Urquhart was assigned to cover the Oath Keepers during a tour of the Sugar Pine gold mine in Oregon after the group of former cops, military, firefighters and other first responders had risen to prominence during a standoff in Nevada over land rights. (Photo by Jim Urquhart/Reuters)

Creative imagery bronze winner. Make-up by Chengbo Sun, China. (Photo by BPOTY/Cover Images)

Goats jumps to cross a stream as they are driven by a herdsman at Dashiwo village, on the outskirts of Beijing January 26, 2015. The Chinese Lunar New Year on February 19 will welcome the Year of the Sheep (also known as the Year of the Goat or Ram). (Photo by Kim Kyung-Hoon/Reuters)

“NASA's Mars rover Opportunity just celebrated its ninth anniversary on Mars – a mission that was originally meant to last just 90 days...” – The Atlantic. Photo: NASA's rover Opportunity visits Victoria Crater, viewed from orbit by the High Resolution Imaging Science Experiment on NASA's Mars Reconnaissance Orbiter in october of 2006. Opportunity is a small dot on the crater's lip, at top right. Opportunity first reached the crater's rim on September 27, 2006. (Photo by NASA/JPL-Caltech/University of Arizona via The Atlantic)

French tennis champion Suzanne Lenglen (1899–1938) high-kicking during a doubles match at the Wimbledon Lawn Tennis Championships. (Photo by Kirby/Topical Press/Getty Images). 1924