Some of London's telephone operators and engineers, trying out their gas masks at the anti-gas civilian training centre in Gloucester, where they were taught how to deal with gas attacks. (Photo by Harry Todd/Fox Photos/Getty Images). 13th February 1937

An infrared portrait from NASA's Spitzer Space Telescope which shows generations of stars is seen in this undated NASA handout image released February 14, 2013. In this wispy star-forming region, called W5, the oldest stars can be seen as blue dots in the centers of the two hollow cavities (other blue dots are background and foreground stars not associated with the region). Red shows heated dust that pervades the region's cavities, while green highlights dense clouds. (Photo by NASA/Reuters/JPL-Caltech/Harvard-Smithsonian/Handout)

Travel photographer Amos Chapple recently crossed into Turkmenistan on a three-day transit visa and was able to photograph many of the sights and monuments in Ashgabat, the capital and largest city. Turkmenistan is a single-party country, a former Soviet state, run by a president at the center of a cult of personality.

Photo: A young couple leave the Alem Entertainment Center in Ashgabat. The current president has a history of breaking obscure records. In 2012 the wheel atop this complex was entered into the Guinness Book of World Records as the world's largest enclosed Ferris wheel. The structure was built at a cost of $90m. (Photo by Amos Chapple via The Atlantic)

An artist draws a tattoo on a woman's arm during a tattoo convention in Ljubljana April 18, 2015. (Photo by Srdjan Zivulovic/Reuters)

A homeless man rests on the side of a street at the old quarter of Yemen's capital Sanaa November 27, 2015. (Photo by Khaled Abdullah/Reuters)

“Zeybeks”. That's Dance, Sunward and Zeybeks. (Photo by Hasan Baglar/2014 Sony World Photography Awards)