The Northern Lights glow green in a spectacular light show above a field of trees frozen solid with snow. (Photo by Jaak Sarv/Solent News & Photo Agency)

Underwater photographer Sarah Lee uses a technique known as “duck diving” to capture these stunning photos of surfers in Hawaii. Surfers “duck dive” under the water to avoid incoming waves so they can get further out to sea. Photo: A surfer comes free from her surfboard. (Photo by Sarah Lee/Caters News)

Ukrainian President Petro Poroshenko gestures during a news conference in Kiev, Ukraine, June 5, 2015. REUTERS/Mykhailo Markiv/Ukrainian Presidential Press Service/Pool

These are the stomach-churning pictures of the swing at the end of the world – a rickety wooden swing hanging over a precipice 2,660 metres above sea level – and not a seatbelt in sight. (Photo by Caters News)

The Thom Browne Fall 2015 collection is modeled during New York Fashion Week, Monday, February 16, 2015. (Photo by Diane Bondareff/AP Photo)

India's Central Reserve Police Force personnel take part in a rehearsal for the Republic Day parade on a cold winter morning in New Delhi January 8, 2014. (Photo by Ahmad Masood/Reuters)

A model poses backstage at the White Carpet Blaque Runway fashion fundraiser at the Causey Contemporary Art Gallery on January 13, 2012 in New York City. (Photo by Jason Kempin/Getty Images)

Men look out from a carriage train as it leaves from the Nizamuddin Railway Station on February 06, 2012 in New Delhi, India. The Nizamuddin Railway Station serves as the main station connecting all major cities, and is served by Northern Railways. (Photo by Daniel Berehulak/Getty Images)