“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)

President Barack Obama speaks to the press in the Briefing Room of the White House April 27, 2011 in Washington, DC. US President Barack Obama released a long form version of his birth certificate after extended criticism by those who do not believe he was born in the United States. (Photo by Brendan Smialowski/Getty Images)

A local resident of Red Hook, Betty Walsh, crosses a flooded street in Red Hook August 28, 2011 in the Brooklyn borough of New York City. While Hurricane Irene has been downgraded to a tropical storm, it has knocked out power to more than 3 million people and is attributed to 15 deaths as it travels up the Eastern seaboard. (Photo by Robert Nickelsberg/Getty Images)

Miu Miu, a Chihuahua, poses at the pre-Westminster Fashion Show at Hotel Pennsylvania ahead of next week's Westminster Kennel Club Dog Show on February 10, 2012 in New York City. (Photo by Michael Nagle/Getty Images)

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)

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)

Labourers break fast outside a shop in a market on the first day of the Muslim holy month of Ramadan in Karachi, Pakistan June 7, 2016. (Photo by Akhtar Soomro/Reuters)