These are the dunes of the Namib Desert, taken by Korea's Kompstat-2 satellite. The blue and white area is the dried riverbed of the Tsauchab river. (Photo by The European Space Agency)

Runner-up. “The City of London, looking towards the Royal Exchange and the Bank of England. The ever-changing London skyline provides many excellent opportunities for cityscape photography, none more exciting than the ebb and flow of traffic at night”. (Photo by Mark Caldon/The Guardian)

Rubber masks depicting U.S. President-elect Donald Trump are seen at the Ogawa Studios, a mask making company, in Saitama, Japan, November 21, 2016. (Photo by Toru Hanai/Reuters)

Cropped shot of a woman flirtatiously touching leg of man in a suit with her foot under the table. (Photo by LightField Studios/Skyfish Digital Media/Getty Images)

This fascinating photo series looks at the bleak isolation of Chernobyl as never before. Employing infrared filters, photographer Vladimir Mitgutin is able to bring out details of decay – an abandoned bus, a radar system, an amusement park, a doll, a sports hall, a piano – frozen in time. Here: Simon – a friendly fox, who often approaches tourists in the exclusion zone, asking for food. (Photo by Vladimir Mitgutin/Caters News Agency)

A woman takes pictures with her mobile phone at a building, which is made by half of a replica of the Qinian Hall of the Temple of the Heaven (R) and half of a western building, at a studio for productions of films and television shows on the outskirts of Shijiazhuang, Hebei province, China, December 3, 2015. (Photo by Reuters/Stringer)

Wildlife photographer Danté Fenolio has headed into areas untouched by sunlight – deep seas, caves and underground – and found creatures that are exploding with colour. Here: The golden harlequin toad has vanished from the wild, and only a small number live on in captivity. A fungus caused them, and many other amphibians, to die out in their home in Central America. (Photo by Danté Fenolio/The Guardian/Johns Hopkins University Press)

Team Strong Silvers member Ngai Hin Kwok, 66, works out as teammate Ng Siu Chi, 57, watches at a stadium in Singapore March 15, 2015. Team Strong Silvers, is a group of senior citizens who train in calisthenics. The trio trains individually at least three times a week, and meets up for joint calisthenics at least twice a month. (Photo by Edgar Su/Reuters)