Models painted in camouflage colours to blend in with the background pose for Chinese artist Liu Bolin's artwork “Dongji”, or Winter Solstice, on the second day after China's capital Beijing issued its second ever “red alert” for air pollution, in Beijing, China, December 20, 2015. In this artwork, Liu wants to express his concerns about China and its people, including air pollution problem, Liu told Reuters. (Photo by Kim Kyung-Hoon/Reuters)

Neil Zeller's snaps were taken across Canada, where he photographs the northern lights dancing across a dark night sky. In one stunning shot, Zeller, 42, even manages to capture a flash of lightning beneath a storm cell while an aurora gives off a magnificent green glow. The photographer, from Calgary, Alberta, describes himself as a night person, and became interested in night photography about 10 years ago. (Photo by Neil Zeller/Caters News)

Men wearing masks and dressed as military members take part in a festival honouring San Silvestre, in the town of Catarina, Nicaragua January 1, 2016. The placard reads, “I'm not afraid, young people off the streets, Ortega you sell our country”, in reference Nicaragua's President Daniel Ortega. (Photo by Oswaldo Rivas/Reuters)

Tribesmen loyal to the Houthi movement perform the Baraa dance during a gathering to show support to the movement in Sanaa, Yemen, May 19, 2016. Bara or Baraa dance is one of the several traditional outdoor dances performed by men in the country of Yemen. Bara dance literally means a dagger dance, where each dancer holds a dagger. The style of the Bara dance differs from tribe to tribe. It is performed on special occasions. (Photo by Khaled Abdullah/Reuters)

Photographer Dotan Saguy visited Cuba expecting to find resentment toward Americans, but he says that, instead, “Every Cuban I met was warm and welcoming despite me being an American”. Here: Several groups of locals relax on the Malecon in Old Havana, Cuba May 1, 2016. Some chat and drink rum while others dive into the warm Caribbean Sea. (Photo by Dotan Saguy)

Indian underprivileged and specially abled grooms and brides in traditional marriage attire arrives to take part in a mass marriage ceremony in Mumbai, India, 29 May 2016. Around 51 couples got married during the ceremony which was organized by Narayan Seva Sansthan, for the underprivileged and specially abled people. From this 51 couples, both the partners are physically disabled in 22 couples, one partner is physically disabled in seven couples and 22 couples are from underprivileged circumstances. (Photo by Divyakant Solanki/EPA)

A handout phptopgraph made avaiable by NASA showing Russian support personnel roll the Soyuz TMA-19M spacecraft after it landed with with with Expedition 47 crew members Tim Kopra of NASA, Tim Peake of the European Space Agency, and Yuri Malenchenko of Roscosmos near the town of Zhezkazgan, Kazakhstan 18 June 2016. Kopra, Peake, and Malenchenko are returning after six months in space where they served as members of the Expedition 46 and 47 crews onboard the International Space Station. (Photo by Bill Ingalls/EPA/NASA)

Nepalese students of Himalayan agriculture college play in mud water in a paddy field to celebrate the National Paddy Day in Badegaun village, Lalitpur, Nepal, 29 June 2016. More than 100 students and teachers of Himalayan agriculture college participated in the National paddy day by planting rice and playing in mud water as Nepal is celebrating National Paddy Day with various event. (Photo by Narendra Shrestha/EPA)