A U.S. army soldier exercises in front of a M270A1 multiple launch rocket system as they prepare for a live-fire training exercise of the 6-37th Field Artillery Regiment at a training area near the demilitarized zone separating the two Koreas, in Cheorwon, South Korea, March 9, 2016. (Photo by Kim Hong-Ji/Reuters)

A doll in a children's gas mask is seen amongst beds at a kindergarten in the abandoned city of Pripyat near the Chernobyl nuclear power plant in Ukraine on March 28, 2016. Deadly radiation still spews from Chernobyl 30 years after the worst nuclear meltdown in history, as a newly built giant arch is pulled into place to cover the stricken reactor for the next century. (Photo by Gleb Garanich/Reuters)

“I’d come to the Altai Mountains on an Adventure Sherpas tour. Our group of 12 was made up mostly of Minnesotans who’d left warm weather and falling leaves for frosty Mongolia. We’d come to sleep in cozy ger tents, the traditional yurt abode of the Mongolian steppe; sip mare’s milk tea; climb mountain glaciers; ride horses to an ancient battle site, and attend the annual Eagle Hunting Festival in Ölgiy...”. – Kathryn Kysar via The Star Tribune. Here: hunter Berek and his eagle outside his home. (Photo by Brad Ruoho/The Star Tribune)

A girl looks out from the window of a “La Sabana” tourist train in La Caro March 1, 2015. The “La Sabana” tourist train that runs through the capital was founded by Eduardo Rodriguez, a railway engineer. Rodriguez has worked on Colombia's railway system his whole life and now, with an air of nostalgia, transports thousands of tourists in renovated steam locomotives that he fixes in Bogota's Central Station which dates back to 1913. (Photo by Jose Miguel Gomez/Reuters)

In 1949, LIFE magazine sent famed photographer Nina Leen to document the daily life of a sassy troupe of young women who had run off and joined the famous Barnum & Bailey Circus in Sarasota, Fla. What developed was a portrait of a sisterhood formed over acrobatics that mixed high-flying wire acts with fashionable high-waisted shorts. Sarasota was once considered “the home of the American circus”. Here: an aerialist smoking while rehearsing for the Ringling Bros. and Barnum & Bailey Circus in Sarasota, FL in 1949. (Photo By Nina Leen/Time Life Pictures/Getty Images)

Thousands gather to rally for marriage equality ahead of a national postal survey on September 10, 2017 in Sydney, Australia. The High Court handed down its decision on Thursday to allow the government's proposed postal ballot survey to go ahead. Ballots with the question “Should the law be changed to allow same-sеx couples to marry?” will be sent to households across Australia on September 12. (Photo by Jonny Weeks/The Guardian)

Balinese man watches Mount Agung volcano almost covered with clouds as he stands at a temple in Karangasem, Bali, Indonesia, Tuesday, September 26, 2017. An increasing frequency of tremors from the volcano indicates magma is continuing to move toward the surface and an eruption is possible, a disaster agency official said Tuesday. Tourists are cutting short their stay to the island, where an eruption would force the airport to close and strand thousands. (Photo by Firdia Lisnawati/AP Photo)

A girl shoots a gun armed with blanks at an weapon exhibition during a military show in St.Petersburg, Russia, Saturday, October 14, 2017. (Photo by Dmitri Lovetsky/AP Photo)