“Aurora Hunters”. Photographers taking part in a photography tour on the Lofoten Islands in Norway, pull over on the side of the road to take a photo of their first ever Aurora Borealis after spotting it from their tour bus. Photo location: Rystad, Lofoten Islands, Norway. (Photo and caption by Mark Gee/National Geographic Photo Contest)

Chinese women holding toy guns dance for a revolutionary song during their daily exercise at a square outside a shopping mall in Beijing, June 29, 2014. About 30 local residents formed this “Nanguan” art group that enjoys performing to revolutionary songs and dance performances as part of their daily fitness activities at night. (Photo by Jason Lee/Reuters)

In this handout artists impression provided by the Russia 2018 Organising Commitee, the Rostov on Don Stadium is shown as proposed and presented as part of the Russia 2018 World Cup bid, on September 29, 2011 in Russia. (Illustration by Russia 2018 via Getty Images)

A North Korean war veteran is decorated with medals as he attends a parade to celebrate the anniversary of the Korean War armistice agreement, Sunday, July 27, 2014 in Pyongyang, North Korea. North Koreans gathered at Kim Il Sung Square as part of celebrations for the 61st anniversary of the armistice that ended the Korean War. (Photo by Wong Maye-E/AP Photo)

A Tampa Bay Buccaneers cheerleader, wear a military-inspired outfit as part of the NFL's Salute to Service program, flips her hair during a game between the Buccaneers and San Diego Chargers in Tampa, on November 11, 2012. (Photo by Phelan M. Ebenhack/Associated Press)

Sydneysiders take part in the “AIME Strut the Streets” in an attempt to break the Guiness record for the world's largest swimwear parade on December 7, 2012 in Sydney, Australia. The event was organised to raise funds and awareness for the not for profit charity organisation, the Australian Indigenous Mentoring Experience. (Photo by Lisa Maree Williams)

People wearing costumes pose for a photograph as they participate in the annual “Zombie Walk” in Bordeaux, France on October 22, 2016. Several hundred people wearing costumes and makeup took part in the walk which was authorized despite the state of emergency. (Photo by Georges Gobet/AFP Photo)

A Belarussian tourist crosses the river as he takes part in “Search and rescue operations – 2016”, a three-day competition, near the village of Priselki, Belarus, November 25, 2016. Photo taken November 25, 2016. (Photo by Vasily Fedosenko/Reuters)