A boy looks for sellable materials close to the burning garbage in the permanent waste land under Sylhet City Corporation for a living, on January 15, 2015. (Photo by Md. Akhlas Uddin/Pacific Press)

A man is silhouetted in front of the Allianz-Arena as he walks his dogs at sunrise in Munich, southern Germany, Friday, April 10, 2015. (Photo by Peter Kneffel/AP Photo/DPA)

A visitor holds up her toy bunny to the aquarium glass in front of Aurora the Russian polar bear at the Sao Paulo Aquarium in Sao Paulo, Brazil, Thursday, April 16, 2015. (Photo by Andre Penner/AP Photo)

This week's full Moon as photographed from on board the International Space Station by NASA astronaut Jeff Williams on August 19, 2016. Jeff is currently Commander of the Space Station for the Expedition 48 crew. (Photo by Jeff Williams/NASA)

A layer of morning mist still covers the fields as the sun rises into the morning sky over Hohenfelden, Thuringia state, Germany, early 07 September 2016. Meteorologists predict the weather to become warm and sunny in the region with temperatures reaching around 256 degrees Celsius. (Photo by Martin Schutt/EPA)

A remote-controlled plane in the form of a witch flies over a neighborhood as the sun sets during Halloween in Encinitas, California, U.S. October 31, 2016. (Photo by Mike Blake/Reuters)

A boy looks on as fire fighters try to extinguish the fire at oil wells, were set on fire by Daesh terrorists as they fled after Al Qayyarah town's cleansing from Daesh militants as the operation to retake Iraq's Mosul from Daesh continues, in Al Qayyarah Town of Mosul, Nineveh, Iraq on November 02, 2016. (Photo by Yunus Keles/Anadolu Agency/Getty Images)

The Bridge “Rakotzbrücke” is pictured against trees in autumn colours in the the eastern German town of Kromlau November 4, 2014. (Photo by Hannibal Hanschke/Reuters)