Pod of dolphins surf effortlessly through the waves in the wild traveling at speeds up to 20 mph. (Photo by Greg Huglin)

A woman dressed up as a zombie participates in a zombie walk in Stockholm, Sweden on August 19, 2017. (Photo by Jonathan Nackstrand/AFP Photo)

Group of blow-up dolls and women. (Photo by Zomi/Getty Images)

Aurora Australis from Beerbarrel Beach, by James Stone. Runner Up: Aurorae. (Photo by James Stone/Astronomy Photographer of the Year)

Roof-topping enthusiast Daniel Lau takes a selfie with high-rise buildings down below as he stands on the top of a skyscraper in Hong Kong, China on August 15, 2017. A craze that began in Russia has now taken hold in Hong Kong, one of the world's most vertical cities. Mr Lau said he had been inspired by Russian climbers and that he was unafraid of the vertiginous heights he scales. (Photo by ImagineChina/Rex Features/Shutterstock)

People line up to buy toilet paper and baby diapers at a supermarket in downtown Caracas January 19, 2015. There's a booming new profession in Venezuela: standing in line. The job usually involves starting before dawn, enduring long hours under the Caribbean sun, dodging or bribing police, and then selling a coveted spot at the front of huge shopping lines. As Venezuela's ailing economy spawns unprecedented shortages of basic goods, panic-buying and a rush to snap up subsidized food, demand is high and the pay is reasonable. (Photo by Jorge Silva/Reuters)