Performers of circus company Circa perform during a photocall for the Edinburgh Festival Fringe on Calton Hill on August 1, 2017 in Edinburgh, United Kingdom. (Photo by Murdo MacLeod/The Guardian)

Athletes in action during the international parachuting competition Mountain Gravity in Quinto, Switzerland, 27 August 2015. Some 200 participants from all over the world are expected to jump at the event running from 22 to 30 August 2015. (Photo by Samuel Golay/EPA)

An installation with a copy of a tank is seen at a villager's house in the village of Vits, Belarus November 8, 2016. (Photo by Vasily Fedosenko/Reuters)

A Hindu devotee lies on a road as she worships the Sun god during the religious festival of Chhath Puja in Kolkata, India October 26, 2017. (Photo by Rupak De Chowdhuri/Reuters)

An Afghan man prepares tea for customers at a roadside tea shop on the outskirts of Jalalabad February 2, 2015. (Photo by Reuters/Parwiz)

A woman poses for her husband alongside a giant camera Thursday, November 7, 2013 outside the Historic Green County Courthouse in Monroe, Wis. Chicago photographer Dennis Manarchy created what's being called the world's largest camera. It's 35-feet long and 12-feet tall it's a working replica of a vintage accordion-style camera that produces 16- by 24-foot prints, the equivalent of a two-story building. The giant camera is on display in Monroe through November 17 because a Monroe company manufactured the specially-built trailer. Manarchy plans to tow the camera around the country to shoot photos of indigenous cultures. (Photo by Mark Hoffman)

Men cover their heads from the sun while riding on a motorcycle during a hot day in Cairo, Egypt, August 17, 2015. A heatwave killed at least 61 people across Egypt from Sunday to Tuesday and caused nearly 600 people to be admitted to hospital, Egypt's health ministry said on state news agency MENA on Wednesday. (Photo by Amr Abdallah Dalsh/Reuters)

“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)