General Atmosphere at 2014 New York Comic Con – Day 3 at Jacob Javitz Center on October 11, 2014 in New York City. (Photo by Laura Cavanaugh/Getty Images)

Dhruva Aliman does a back somersault as he dismounts from a slackline on the beach at Santa Monica, California on October 19, 2014. Slackline is a balance sport where a line of webbing is adjusted at different levels of tension between two anchor points and participants (called slackers) perform tricks and stunts including somersaults. (Photo by Mark Ralston/AFP Photo)

A P-51 Mustang named “Charlotte's Chariot” from the Southern Heritage Air Foundation flies past a cloud of smoke and fire from a nearby battle reenactment during the Wings Over Houston Airshow in Houston, on Saturday, November 1, 2014. Battle reenactments are part of the yearly show held at Ellington Airport. (Photo by Kar Hlava/AP Photo/Bay Area Citizen)

Waura Indians wrestle during this year's “quarup”, a ritual held over several days to honour in death a person of great importance to them, in Xingu National Park, Mato Grosso State, Brazil August 25, 2013. (Photo by Ueslei Marcelino/Reuters)

This tiny hedgehog is in a prickly position as hes unable to grow spikes, leaving him needing round-the-clock care. The woodland critter was found with no spikes and has been taken in by a family hoping to nurse him back to health so he can be released into the wild. Named Mr Prickleless, the hedgehog was rescued by Dina Nixon and her daughter Jennifer, 25, after being taken into a rescue centre in December last year. It is not known what happened to his spikes, but Dina has vowed that if they ever do return he will be returned to the wild. But for now the hedgehog has taken shelter in a rabbit hutch in her garden. (Photo by Caters News Agency)

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 Army Sikorsky VH-34s Choctaw helicopter once used to transport President Dwight D. Eisenhower sits in a field at the 309th Aerospace Maintenance and Regeneration Group boneyard Thursday, May 14, 2015 at Davis-Monthan Air Force Base in Tucson, Ariz. President Eisenhower became the first chief executive to be transported by helicopter. Presidents Eisenhower and John F. Kennedy were transported in VH-34 helicopters and VH-34's served as “Army One” from 1958 through 1963. (Photo by Matt York/AP Photo)

Jean-François Leroy launched Visa Pour l’Image, the international photojournalism festival, in Perpignan in 1989. Before heading up the festival, Leroy was shooting reportage for the agency Sipa Press and also working for Photo-Reporter, Le Photographe, Photo-Revue and Photo Magazine. He is the chairman of the company Images Evidence. Photo: 2008 Visa d'or Feature: Brent Stirton. Conservation Rangers from an Anti-Poaching unit work with locals to evacuate the bodies of four Mountain Gorrillas killed in mysterious circumstances in the park, July 24, 2007, Virunga National Park, Eastern Congo. (Photo by Brent Stirton/Exclusive by Getty Images)