Internally displaced Syrian children stand at the entrance of their makeshift shelter that is an underground cave in Om al-Seer, southern Idlib countryside, Syria December 26, 2015. (Photo by Khalil Ashawi/Reuters)

ESA astronaut Samantha Cristoforetti on the International Space Station 3 February 2015 during her Futura mission. Samantha is living and working on the Station as part of the Expedition 42 crew. Picture released on February 10, 2015. (Photo by ESA/NASA)

Doutzen Kroes and Candice Swanpoel arrive at the Mert Alas x Marcus Piggot book launch party at Public Hotelon September 7, 2017 in New York City. (Photo by Pierre Suu/GC Images)

Indian passengers travel on a local train in New Delhi, India, October 2017. Constructed in 1975 to bypass the crowded and passenger-heavy Old Delhi, New Delhi and Hazrat Nizamuddin railway stations, the railway line once used to be the lifeline of the capital. (Photo by Ankur Dutta/Barcroft Media)

Brian Anderson has been taking images of Glasgow for 20 years, spotlighting both the light and dark side of life. Brian, 40, said: “Glasgow is full of character. It’s a nice city, it’s a crazy city and I want to show all that”. Photo: Police look on as a man tries to break up brawling women in Queen Street. (Photo by Brian Anderson)

“Daredevil Nik Wallenda became the first person to walk on a tightrope across the Niagara Falls, taking steady, measured steps June 15, 2012 for 1,800 feet across the mist-fogged brink of the roaring falls separating the U.S. and Canada”. (Photo by John Moore/David Duprey/AP Photo)

Andy Swan “Zippy the Clown” from Sacramento, California, drives his “elelphant” car during a break at the 2011 Clowns of America International Convention on April 15, 2011 in Anaheim, California. Several hundred clowns, from all over the United States and from as far as Puerto Rico and Germany, are attending the convention to compete in skits and hone their skills in the art of balloon-making and face-painting. (Photo by Kevork Djansezian/Getty Images)