Merit: A Night at Deadvlei. The night before returning to Windhoek, we spent several hours at Deadveli. The moon was bright enough to illuminate the sand dunes in the distance, but the skies were still dark enough to clearly see the milky way and magellanic clouds. Deadveli means “dead marsh. The camelthorn trees are believed to be about 900 years old, but have not decomposed because the environment is so dry. (Photo and caption by Beth McCarley/National Geographic Traveler Photo Contest)

This huge male orangutan is having a right old laugh as he squints his eyes and shows his huge teeth. The orangutan, called Bimbo, was relaxing on a platform around 5m high in his enclosure when he broke out into a laugh. But his happy smile soon disappeared when another orangutan came over to see what was going on. Bimbo – the only male in the group of five apes at Leipzig Zoo, in Germany - appears to be laughing in much the same way as a human would. (Photo by Martina Radtke/Solent News)

A man stands at a passenger train damaged in a collision with a freight train in Moscow region May 20, 2014. The passenger train on its way to Moldova collided with a freight train near Moscow on Tuesday, killing at least four people and injuring 15, a spokeswoman for Russia's Emergencies Ministry said. The reason for the collision, near the town of Naro-Fominsk 55 km (34 miles) southwest of Moscow, was not immediately clear. (Photo by Grigory Dukor/Reuters)

Three Boeing 737 fuselages lie on an embankment on the Clark Fork River after a BNSF Railway Co train derailed Thursday near Rivulet, Montana in this picture taken July 4, 2014. A train derailment in Montana this week damaged a shipment of jetliner fuselages and other large parts on its way to Boeing Co factories in Washington state from Spirit Aerosystems, Boeing said on Saturday. (Photo by Kyle Massick/Reuters)

The stunning Milkyway in Midwestern U.S.A. captured by photographer Randy Halverson in 2013. The stunning skies in Midwestern U.S.A. captured by photographer Randy Halverson. The videographer captured rare footage of the Milky Way, the elusive Northern Lights and raging night storms in some of the most isolated regions of the U.S.A. The footage, which spans the skies of South Dakota, Wyoming and Utah, was taken between spring and autumn 2013. The 47-year-old spent 40 nights scattered across the eight-month period sat near his camera to capture the clear footage. Randy from Kennebec, South Dakota has been shooting timelapse for over 4 years. (Photo by Randy Halverson/Barcroft Media)

Up to 35% of Mongolians still live a nomadic life, depending on their land to survive. But environmental changes, particularly desertification, means this way of life is under threat. Korean photographer Daesung Lee’s Futuristic Archaeology images show billboard-size backdrops of lush steppe contrasting with actual scenery as former nomads enact scenes of hunting, herding and Mongolian wrestling. (Photo by Daesung Lee)

Joshua Patino stands on a ladder to put finishing touches on a giant dinosaur exhibit at PAX East in the Boston Convention and Expo Center, Thursday, April 21, 2016, in Boston. PAX East, an annual celebration of gaming culture, is expected to draw tens of thousands of visitors Friday through Sunday. It's a place where serious gamers can preview unreleased video games and devices, compete in tournaments, hear live music and meet others for whom gaming is a way of life. (Photo by Elise Amendola/AP Photo)

Orthodox Christian pilgrims from Abkhazia walk along the Via Dolorosa (Way of Suffering), during the Good Friday procession in Jerusalem's old city on April 29, 2016. Thousands of pilgrims took part in processions along the route where, according to tradition, Jesus carried the cross during his last days. (Photo by Gali Tibbon/AFP Photo)