Ukrainian Air Force officers attend a graduation ceremony at the National University of Defence of Ukraine in Kiev, April 24, 2015. (Photo by Gleb Garanich/Reuters)

National Geographic has created “Air, Land & Sea: the 50 greatest wildlife photographs” exhibition. Here: CT4 Crocodile cave on the Salamat river. Set up with Nathan Williamson last chip rain came while we were with the nomads. (Photo by Michael Nichols/National Geographic)

Miss Netherlands, Ona Moody walks onstage during The 71st Miss Universe Competition National Costume Show at New Orleans Morial Convention Center on January 11, 2023 in New Orleans, Louisiana. (Photo by Josh Brasted/Getty Images)

“Winter Climbing from inside Ben Nevis”. The view from inside the mountain, as a winter climber passes through the cave on Minus Three gully. Photo location: Ben Nevis, Fort William, Scotland. (Photo and caption by Daniel Wildey/National Geographic Photo Contest)

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)

Actors wearing masks of Syrian President Bashar al-Assad and Russian Prime Minister Vladimir Putin perform with body bags during a demonstration outside United Nations headquarters on January 24, 2011 in New York City. Protesters called on the U.N. Security Council to pass a resolution to attempt to halt al-Assad's crackdown on the Syrian uprising. (Photo by Mario Tama/Getty Images)

Dr. Christopher Brown (R), the Director of the Ashmolean, talks with Colin Harrison, the Ashmolean's Senior Curator of European Art, in front of a painting by Edouard Manet entitled “Portrait of Mademoiselle Claus” from 1868 in the Ashmolean Museum on February 24, 2012 in Oxford, England. The painting has been sold to a foreign buyer for 28.35 million GBP, however the Government has extended a temporary export bar on the artwork until August to give the Ashmolean an opportunity to raise funds to retain the painting in the UK. (Photo by Oli Scarff/Getty Images)

Mystical Forest. Tracey Jennings photographed this seven-gill shark in a kelp forest just off the shore of Simon's Town near Cape Town, South Africa. You don't need to travel far from cities to visit Narnia. This 7 gill shark was photographed in a kelp forest just off the shore of Simonstown near Cape Town, South Africa. (Photo by Tracey Jennings/National Geographic Travel Photographer of the Year Contest)