In this photo taken on Monday, October 27, 2014, a cactus stands at a broken window in a damaged house after shelling not far from Donetsk airport in the town of Donetsk, eastern Ukraine. Donetsk, which has lost about 400,000 of its 1 million pre-war population, is bracing to a winter ahead. In a climate like eastern Ukraine's, where temperatures typically stay below zero all winter, the damage to the critical infrastructure and lack of effort to provide adequate shelter to people whose homes were destroyed could literally mean a death from the cold. (Photo by Dmitry Lovetsky/AP Photo)

Swiss pilot Bertrand Piccard prepares for a test flight of the solar-powered Solar Impulse 2 experimental aircraft in Payerne November 13, 2014. The aircraft, weighing 2.4 tons with a wingspan of 72 meters, is fitted with more than 17,000 solar cells. An attempt to fly around the world in stages using only solar energy will be made in 2015. (Photo by Ruben Sprich/Reuters)

Belgian animal sculptor Emmanuel Janssens Casteels works at his desk next to a replica of a Smilodon, an extinct genus of machairodont felid, in his workshop in Prayssas December 3, 2014. Casteels' company OPHYS specializes in life-size reconstructions and the sculpting or moulding reproductions of animals and hyper-realist fossils. His reconstructions are exhibited in museums and theme parks. (Photo by Regis Duvignau/Reuters)

A worker carries a bag of salt after collecting it from a pond at the Maras mines in Cuzco December 3, 2014. Salt has been obtained in Maras since pre-Incan times by evaporating highly salty local subterranean stream water. The water is intricately channelled through constructions, flowing gradually down onto several hundred ancient terraced ponds. From each pond, a local member of the mine cooperative can produce 150 to 200 kilos per month which can be sold in the markets at $0.34 per kilogram, according to miners. (Photo by Enrique Castro-Mendivil/Reuters)

Dutch artist Daan Roosegaarde paid homage to Vincent Van Gogh's famous “Starry Night” painting by creating a glowing bike path relying on solar-powered LED lights. The 650-yard route which opened November 12, 2014 extends between Eindhoven and Neunen, Netherlands, where Van Gogh spent part of his life. Its the first event marking the 125th anniversary of Van Gogh's death July 29, 2015. (Photo by Pim Hendriksen/Studio Roosegaarde)

A security personnel detains a suspect after a blast in Kabul, November 25, 2014. A powerful explosion shook houses in the diplomatic quarter of Kabul on Tuesday, but there were no casualties in the second such incident in the Afghan capital in a single day, officials said. “Someone threw a hand grenade and he was apprehended”, said Sediq Sediqqi, a spokesman for the interior ministry. The suspect was being interrogated but his motive and target were still unclear, he added. (Photo by Omar Sobhani/Reuters)

A tunnel with electric switches are seen in Josip Broz Tito's underground secret bunker (ARK) in Konjic, October 16, 2014. In the early 1950s, Josip Broz Tito, the late leader of the former Yugoslavia, ordered the building of the secret bunker, located 900 feet (270 m) underground and near the Bosnian town of Konjic, to safeguard the country's ruling class in case of a nuclear attack. Construction at the complex, which had a cost equivalent price tag of $4.6 billion, continued until 1979, the year before Tito died. (Photo by Dado Ruvic/Reuters)

In this November 18, 2014 photo, Murshida, 12, sits on the lap of her mother Marjina as the train leaves for their village in West Bengal, at a railway station in New Delhi, India. Six months ago, Marjina stepped off a train in New Delhi with her two children, hoping to find a better life after her husband abandoned them without so much as a goodbye. The family spent their days at a landfill picking through other people’s garbage to find salvageable bits to resell or recycle. After six months of poverty, illness and shame, they returned to that train station in New Delhi, headed back to an uncertain future to their hometown in West Bengal. (Photo by Altaf Qadri/AP Photo)