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)

An Afghan National Army (ANA) soldier assigned to the Mobile Strike Force Kandak fires a RPG-7 rocket-propelled grenade launcher during a live-fire exercise supervised by the Marines with the Mobile Strike Force Advisor Team on Camp Shorabak, Helmand province, Afghanistan, May 20, 2013. The Marines with the Mobile Strike Force Advisor Team instructed and mentored their ANA counterparts on how to properly utilize their weapons systems. (Photo by SSgt Ezekiel R. Kitandwe/RCT 7)

As the world marks International Women's Day on Wednesday, whose theme this year focuses on “women in the changing world of work”, the Israeli military says it is ahead of the curve in providing combat roles for female soldiers. Here: A female Israeli soldier from the Haraam artillery battalion fixes her hair in the women's living quarters at a military base in the Israeli-occupied Golan Heights March 1, 2017. (Photo by Nir Elias/Reuters)

Miesha Tate, UFC women's bantaweight shows the media how to fight during a UFC press conference at Akasaka Garden City on August 26, 2014 in Tokyo, Japan. (Photo by Atsushi Tomura/Getty Images)

Revellers take part in the the 70th Annual Columbus Day Parade in New York, October 13, 2014. (Photo by Eduardo Munoz/Reuters)

From rural life in India to a chick growing inside its embryo and a sea turtle eating a purple jellyfish, the Society of Biology has released their stunning photography competition shortlist. Here: “Spectral Tarsier”. Tangkoko, Northern Sulawesi, Indonesia: Spectral tarsier by Wolfgang Weinhardt. (Photo and caption by Wolfgang Weinhardt/UK Society of Biology Photography Award 2014)

“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)

ATTENTION! All pictures are presented in high resolution. To see Hi-Res images – just TWICE click on any picture. In other words, click small picture – opens the BIG picture. Click BIG picture – opens VERY BIG picture.

A young Shiite Muslim child participates in a Muharram procession in Ahmadabad, India, Sunday, October 9, 2016. (Photo by Ajit Solanki/AP Photo)