A photo taken on August 29, 2014, shows Mount Tavurvur erupting in eastern Papua New Guinea, spewing rocks and ash into the air, forcing the evacuation of local communities and international flights to be re-routed. Mount Tavurvur, which destroyed the town of Rabaul when it erupted simultaneously with nearby Mount Vulcan in 1994, rumbled to life early in the morning on the tip of the remote island of New Britain. (Photo by Oliver Bluett/AFP Photo)

Wedges of an orange generate enough current and electrical juice – 3.5 volts – to power an LED. The fruit’s citric acid helps electrons flow from galvanized nails to copper wire in this 14-hour exposure. This image was published in September’s Visions of Earth, a trio of photos that appear in each issue of National Geographic. (Photo by Caleb Charland/National Geographic)

U.S. Marine Lt. Ben Reid from 1/2 Charlie Company of Task Force Tarawa waits to be medivaced after being hit with shrapnel and a machine gun round, in the southern Iraqi city of Nasiriyah, on March 23, 2003. The Marines suffered a number of deaths and casualties during gun battles throughout the city. (Photo by Joe Raedle via The Atlantic)

People walk through crop circles in a cornfield near Raisting, Germany, on July 28, 2014. According to media reports, a balloonist had discovered the circle some days ago. Since then, hundreds of people came to the field to watch it, however it is unclear who did create the pattern. (Photo by Karl-Josef Hildenbrand/DPA)

In this May 17, 2015, photo, two men walk past pagodas at Ngwe Saung beach, Pathein township, about 145 miles from Yangon, Myanmar. (Photo by Khin Maung Win/AP Photo)

A woman takes a selfie in front of a Lunar New Year display featuring sheep at a shopping mall in Hong Kong, February 13, 2015. (Photo by Bobby Yip/Reuters)

A Ukrainian man stands in protest in front of gunmen in unmarked uniforms as they stand guard in Balaklava, on the outskirts of Sevastopol, Ukraine, Saturday, March 1, 2014. (Photo by Andrew Lubimov/AP Photo)

“A snapshot from mountaineer's life”. Have you ever wondered how does a mountaineer's day start? I will give you a hint: you wake up at 3 am, set the stove, wake up your partner, pretend it is warm, quickly consume a high-calorie breakfast, watch your friends slowly ascending the icy slopes of your dream summit with their tiny head torches glimmering against perfectly blue ice, and hope for the good weather. One would ask: why all this trouble? The answer is easy: for the love of the adventure and the unknown. Location: Chamonix, Haute Savoye, France. (Photo and caption by Kamil Tamiola/National Geographic Traveler Photo Contest)

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