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)

Heugh Breakwater by Caroline Walker. Winner in the Coastal Views category. (Photo by Caroline Walker/Sea View Photography Competition 2020)

A tow car for the children's “Grand Prix” races which take place in a parking lot in Livonia, Michigan a suburb of Detroit, circa 1955. (Photo by Three Lions/Getty Images)

“Misty Rainbow”. A rainbow appears over tea fields in Tangerang Selatan, Indonesia. (Photo by Dani Agus Purnomo/Royal Meteorological Society’s Weather Photographer of the Year Awards)

An Afghan girl carries water on her back as she climbs a hill in Kabul, Afghanistan February 20, 2017. A growing population is straining water supplies in Afghanistan's capital, forcing those who can afford it to dig unregulated wells ever deeper to tap a falling water table. Finding water in arid Afghanistan is virtually always a challenge, but a drop in the groundwater level in Kabul caused by overuse and drought is making it even more difficult for residents, especially the poor. (Photo by Omar Sobhani/Reuters)

A female army recruit attends a base training at the armored battalion in Setermoen, northern Norway on August 11, 2016. Norway has become the first NATO member to have compulsory conscription for women as well as men in the army. Recently, the first batch of army recruits joined the ranks in The Armored Battalion in the Norwegian Army located in Setermoen in northern Norway. (Photo by Kyrre Lien/AFP Photo)

Relatives clean the body of Paul Sampe Lumba who has been dead for seven yeas during the Ma'nene ritual at Panggala Village on August 26, 2016 in Toraja, Indonesia. The Ma'nene ritual in performed during a ceremony every three years, where the dead are exhumed for a change of clothes, among the people of Toraja as an expression of the love of the surviving family. (Photo by Sijori Images/Barcroft Images)

These Northern Lights “rainbows” have turned the sky greener than the Earth below. Vitaly Istomin, 26, spent several nights in freezing conditions under the stars in northern Russia’s Khibiny Mountains to capture the aurora’s “rainbows”. (Photo by Vitaly Istomin/Caters News Agency)