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)

A Thai devotee in a state of trance screams while holy water is sprayed as thousands race towards the edifice of the founder monk during the annual Tattoo fesitval at Wat Bang Phra on March 7, 2009 in Nakhom Pathom, Thailand. Some men take on the characteristics of sacred animals that have been carved onto their skin. Thousands of believers from all over Thailand come to take part in one of the country's most bizarre festivals about 50 miles outside Bangkok to pay respect to the temple's monks who are master tattooist. In Thai culture the tattoo or Thai word sak yant is worn as a symbol of spiritual and physical protection, many believe that the tattoo have mystical powers. Many tattoo fanatics choose to have monkeys and tigers as well as the Khmer/Cambodia ancient script on their bodies. (Photo Paula Bronstein/Getty Images)

Members of the Prizma Ensemble wearing full solid-coloured bodysuits take part in a festival for the Jewish holiday of Hanukkah, in Jerusalem December 26, 2016. (Photo by Amir Cohen/Reuters)

Members of the Prizma Ensemble wearing full solid-coloured bodysuits walk pest ultra orthodox jewish men as they take part in the 6th Jane's walk Jerusalem in Jerusalem, Israel May 6, 2016. Jane's Walk is a global walking tour movement, inspired by US-Canadian author and activist Jane Jacobs. (Photo by Baz Ratner/Reuters)

These Arab recruits line up in a barracks square in the British Mandate of Palestine, on December 28, 1940, for their first drill under a British solider. Some 6,000 Palestinian Arabs signed up with the British Army during the course of World War II. (AP Photo)

World medieval jousting champion Rod Walker poses before next month’s St Ives Medieval Faire, the only solid wood lance joust tournament in the southern hemisphere in Sydney, Australia on August 26, 2016. (Photo by Dan Himbrechts/AAP)

Astronomer, space scientist and meteorologist Andrea Opitz, senior research associate of the Space Physics and Space Technology Department of Hungarian Academy of Sciences (MTA) Wigner Research Centre for Physics (2R) wears a space suit during a cosmology exhibition in Budapest, Hungary, 03 March 2016. The photo series was created to mark the International Women's Day (IWD), which was marked for the first time in 1911 and is celebrated on 08 March since 1913. (Photo by Bea Kallos/EPA)