Rooftops of solar powered houses are pictured in Ota, 80 km northwest of Tokyo in this October 28, 2008 file photo. One by one, Japan is turning off the lights at the giant oil-fired power plants that propelled it to the ranks of the world's top industrialised nations. With nuclear power in the doldrums after the Fukushima disaster, it's solar energy that is becoming the alternative. Solar power is set to become profitable in Japan as early as this quarter, according to the Japan Renewable Energy Foundation (JREF), freeing it from the need for government subsidies and making it the last of the G7 economies where the technology has become economically viable. (Photo by Yuriko Nakao/Reuters)

Juno, a Beluga whale, greets a young viewer at the Mystic aquarium in Connecticut, USA on December 5, 2015. (Photo by Tim Clayton/Corbis)

Anand Varma, a U.S. photographer working for the National Geographic, won the First Prize in the Nature Category, Stories, of the 2015 World Press Photo contest with his series of pictures, which includes this one of spores of a fungus landing on an ant, penetrating its exoskeleton and entering its brain, compelling the host to leave its normal habitat on the forest floor and scale a nearby tree, in this picture taken January 22, 2014 and released by the World Press Photo on February 12, 2015. (Photo by Anand Varma/Reuters/National Geographic/World Press Photo)

SpaceX’s Dragon spacecraft, March 6, 2014. SpaceX's Falcon 9 rocket and Dragon spacecraft launched from Launch Complex 40 at the Cape Canaveral Air Force Station, Florida, for their third official Commercial Resupply (CRS) mission to the orbiting lab on April 18, 2014. Dragon returned to Earth with a parachute-assisted splashdown off the coast of southern California on May 14, 2014. Dragon is the only operational spacecraft capable of returning a significant amount of supplies back to Earth, including experiments. (Photo by Ron Lin/SpaceX Photos)

A woman cartwheels through the Coachella Valley Music and Arts Festival in Indio, California April 10, 2015. (Photo by Lucy Nicholson/Reuters)

Men transport a sheep on their motorcycle after buying it at an old cattle market named “Al Emam Market” ahead of the Muslim festival Eid al-Adha in Cairo, Egypt, September 19, 2015. Muslims across the world are preparing to celebrate the annual festival of Eid al-Adha or the Festival of Sacrifice, which marks the end of the annual hajj pilgrimage, by slaughtering goats, sheep, cows and camels in commemoration of the Prophet Abraham's readiness to sacrifice his son to show obedience to Allah. (Photo by Amr Abdallah Dalsh/Reuters)

A rebel fighter carries his weapon as he moves through a hole in a wall in the old city of Aleppo near the frontline against forces loyal to Syria's President Bashar al-Assad December 28, 2014. (Photo by Jalal Al-Mamo/Reuters)

Devotees ride on the roof of a train as they return to the city after attending the final prayers on the first phase of Bishwa Ijtema in Dhaka January 11, 2015. Hundreds of thousands of pilgrims congregated in the Bangladeshi capital Dhaka as the first phase of this year's Bishwa Ijtema, one of the biggest Islamic gatherings in the world after the Haj in Saudi Arabia, came to an end. (Photo by Reuters/Stringer)