Attnedees dressed in Zombie outfits walk down the Gaslamp Quarter outside of the 2015 Comic-Con International in San Diego, California July 8, 2015. (Photo by Sandy Huffaker/Reuters)

British tourists snap a cheeky selfie with a monkey at the Ubud Monkey Forest in Bali, Indonesia, August 4, 2015. George Benton, 22, from Paignton, Devon was visiting the Sacred Monkey Forest Sanctuary in Ubud, Bali whilst traveling with his girlfriend Chloe when the couple snapped a surprise shot with Balinese long-tailed monkey using a “selfie stick”. “We couldn't believe our luck when we looked back at the photos, he looked straight into the camera!” said George, who went on to reward the cheeky chap with a banana for giving the couple such a memorable photo. (Photo by George Benton/Splash News)

In this August 28, 1963 file photo, the top of the Washington Monument and part of a U.S. flag are reflected in the sunglasses of Austin Clinton Brown, 9, of Gainesville, Ga., as he poses at the Capitol where he joins others in the March on Washington. (Photo by AFP Photo)

Large trumpet vines spread across electrical lines next to a highway in Kinston, N.C., on June 23, 2014. (Photo by Janet S. Carter/Kinston Free Press via AP Photo)

“NASA's Mars rover Opportunity just celebrated its ninth anniversary on Mars – a mission that was originally meant to last just 90 days...” – The Atlantic. Photo: NASA's rover Opportunity visits Victoria Crater, viewed from orbit by the High Resolution Imaging Science Experiment on NASA's Mars Reconnaissance Orbiter in october of 2006. Opportunity is a small dot on the crater's lip, at top right. Opportunity first reached the crater's rim on September 27, 2006. (Photo by NASA/JPL-Caltech/University of Arizona via The Atlantic)

An Indian Sadhu, or Hindu holy man, sits for a community feast at the Sangam, the confluence of the Rivers Ganges, Yamuna and mythical Saraswati, during the annual month-long Magh Mela religious fair in Allahabad, India, Friday, January 16, 2015. Hundreds of thousands of devout Hindus are expected to take holy dips at the confluence during the astronomically auspicious period of over 45 days celebrated as Magh Mela. (Photo by Rajesh Kumar Singh/AP Photo)

An adorable baby owl has proved to be a real heart-breaker thanks to its heart-shaped head. Although Griffin the Lesser Sooty Owl might look like a feather duster, the tiny eight-week old chick will soon be ready to fly. And the heart outline that surrounds his giant eyes and beak means he is set to be the star of the bird show at Taronga Zoo, Sydney. (Photo by Caters News Agency)

“Double head vulture”. On the day of windy days during raptors migration some people in my country start to catch these tired raptors, so in this day we go to photograph some raptors and we saw these tow tired vultures, so we start to drag them away from the hunters until they reach a good hidden place, to make them safe until they start a new journey. Photo location: Kuwait. (Photo and caption by Mohd Khorshed/National Geographic Photo Contest)