A couple watches the sunset over a sea of fog covering the Geneva Lake from Chardonne, Switzerland, 28 December 2015. (Photo by Jean-Christophe Bott/EPA)

A walruses at Hagenbeck Zoo in Hamburg, Germany on July, 7, 2015. (Photo by Werner Struss/Startraks action)

A man from the Dani tribe cuts the head of a pig after cooked by traditional way which is use burned hot stones at Obia Village on August 9, 2014 in Wamena, Papua, Indonesia. The stone-age Dani tribe live a traditional existence in the Baliem Valley, which is situated 1600 metres above sea level in the heart of the Cyclops Mountains. (Photo by Agung Parameswara/Getty Images)

In this September 1, 2014 photo released by the U.S. Geological Survey, fluid lava streams from the June 27 lava flow from the Kilauea volcano in Pahoa, Hawaii. The June 27 lava flow is named for the date it began erupting from a new vent. The Hawaiian Volcano Observatory issued a warning Thursday, September 4, 2014 to a rural community in the path of a lava flow on Hawaii's Big Island, as the molten rock moved to within a mile of homes. Observatory scientists said lava from the Kilauea volcano could reach the Kaohe Homesteads in five to seven days if it continues advancing through cracks in the earth. (Photo by AP Photo/U.S. Geological Survey)

Iraq's second largest city, Mosul, is locked under the rule of extremists from the Islamic State group trying to purge it of everything they see as contradicting their stark vision of Islam. A trove of photographs now housed at the Library of Congress offers a glimpse of a different Mosul – before wars, insurgency, sectarian strife and now radicals' rule. The scenes were taken in the autumn of 1932 by staff from the American Colony Photo Department during a visit to Iraq at the end of the British mandate. (Photo by AP Photo)

A Russia-backed rebel looks at the flag covered body of an Ukrainian serviceman in Debaltseve, Ukraine, February 20, 2015. The struggle for the strategic rail hub, Debaltseve, a sleepy town with a pre-war population of 25,000 people, left the town in ruins and became one of the darkest pages in the ongoing conflict in eastern Ukraine, which has already killed more than 6,000 people. (Photo by Vadim Ghirda/AP Photo/File)

The Lumix GX1 single lens reflex (SLR) camera with 14-42 mm powerzoom lens is displayed at the Panasonic booth at the 2012 International Consumer Electronics Show at the Las Vegas Convention Center January 10, 2012 in Las Vegas, Nevada. The new camera comes with an external viewfinder and flash and an ISO up to 12,800. The camera as shown sells for USD 949; the camera body alone is USD 799. (Photo by Ethan Miller/Getty Images)

Apollo 9 Command/Service Modules (CSM) nicknamed “Gumdrop” and Lunar Module (LM), nicknamed “Spider” are shown docked together as Command Module pilot David R. Scott stands in the open hatch. Astronaut Russell L. Schweickart, Lunar Module pilot, took this photograph of Scott during his EVA as he stood on the porch outside the Lunar Module. Apollo 9 was an Earth orbital mission designed to test docking procedures between the CSM and LM as well as test fly the Lunar Module in the relative safe confines of Earth orbit. (Photo by NASA)