Servicemen of “Kiev 12” military defence battalion react as they take part in a welcoming ceremony in central Ukrainian capital Kiev December 6, 2014. Servicemen of the battalion returned to Kiev after taking part in fighting in eastern Ukraine. (Photo by Gleb Garanich/Reuters)

In this Monday, March 10, 2014 photo, a 9,000 year-old mask is on display at the Israel Museum in Jerusalem. The exhibition called “Face To Face” shows eleven stone masks, said to have been discovered in the Judean desert and hills near Jerusalem, which date back 9,000 years and offer a rare glimpse at some of civilization's first communal rituals. (Photo by Tsafrir Abayov/AP Photo)

NASA astronaut Reid Wiseman and European Space Agency astronaut Alexander Gerst (not shown) works outside the space station's Quest airlock in the first of three spacewalks for the Expedition 41 crew aboard the International Space Station in this NASA image released October 8, 2014. (Photo by Reuters/NASA)

In this Friday, December 5, 2014 photo, Iranian volunteer Asal Moghaddam plays with dogs at the Vafa Animal Shelter in the city of Hashtgerd 43 miles (73 kilometers) west of the capital Tehran, Iran. More than 500 dogs find care and affection at the Vafa Animal Shelter, which was established through an endowment in 2004 and is the country’s only licensed animal refuge. (Photo by Vahid Salemi/AP Photo)

Clowns take part in the annual pilgrimage to the Basilica of Our Lady Guadalupe to pay homage to the Virgin of Guadalupe in Mexico City December 16, 2014. Dressed in colourful costumes, hundreds of clowns from all over Mexico walked towards the Basilica to give thanks to the virgin for the work they have received. (Photo by Carlos Jasso/Reuters)

A diver wearing a Santa Claus costume feeds a sunfish to attract visitors at the Hakkeijima Sea Paradise aquarium in Yokohama, suburban Tokyo on December 17, 2014. Christmas attractions will be held till Christmas Day. (Photo by Yoshikazu Tsuno/AFP Photo)

Community members look for the nameplates of their loved ones Tuesday, December 9, 2014 at Myers Funeral Service and Crematory in Porterville, Calif. during the 20th year of the memorial tree lighting. (Photo by Chieko Hara/AP Photo/The Porterville Recorder)

A participant wearing a tiger mask performs during the “Paseo del Pendon”, a traditional artistic march in Chilpancingo, December 21, 2014. The “Paseo del Pendon” (walk banner) is a traditional celebration in the streets of Chilpancingo to mark the begin of the the year-end festivities in the city. (Photo by Jorge Dan Lopez/Reuters)