A view of a large poster depicting Russian opposition leader Alexei Navalny behind bars with a dove freeing him from detention, by an unidentified street artist known as Harry Greb, in downtown Rome, Italy, 25 January 2021. Navalny was detained after his arrival to Moscow from Germany on 17 January 2021. A Moscow judge on 18 January ruled that he will remain in custody for 30 days following his airport arrest. Navalny urged Russians to take to the streets to protest against President Putin's rule. (Photo by Fabio Frustaci/EPA/EFE)

People wearing protective face masks amid the coronavirus disease (COVID-19) outbreak are seen near foodstuffs, which are displayed for sale on a car in Omsk, Russia on December 4, 2020. (Photo by Alexey Malgavko/Reuters)

A British Spitfire and an American P-51 Mustang from Ultimate Warbird Flights take to the Northamptonshire on August 14, 2020 skies to mark the 75th anniversary of VJ Day. (Photo by Richard Pohle/The Times)

A fox pounces on a mouse in the snowy hills on the border of the Czech Republic and Slovakia. (Photo by Johnny Krüger/Mediadrumimages)

Two baby orangutans play with each other at the wildlife department in Kuala Lumpur, Malayasia, October 19, 2015. The Malaysian wildlife department in July seized two baby Sumatran orangutans, found in duffel bags, from traffickers who were attempting to sell them to buyers in Malaysia. According to local media, the orangutans will be returned to Medan, Indonesia on Tuesday. The illegal wildlife trade is estimated to be $8 billion a year worldwide, according to TRAFFIC, a wildlife trade monitoring network. (Photo by Olivia Harris/Reuters)

Farmers ride home on a tractor pulling an overloaded trailer full of straw in a village outside Faisalabad, Pakistan May 3, 2017. (Photo by Caren Firouz/Reuters)

Clearing skies await a tripod-toting photographer looking for a spot to capture the early-morning light at Portland Head Light, Thursday, January 17, 2013, in Cape Elizabeth, Maine. (Photo by Robert F. Bukaty/AP 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)