The northern lights, or aurora borealis, appear in the sky over the Bamburgh lighthouse at Stag Rock in Northumberland, England on September 28, 2016. (Photo by Owen Humphreys/PA Wire via ZUMA Press)

Charcoal burner Zygmunt Furdygiel fires wood inside a charcoal furnace at a charcoal making site in the forest of Bieszczady Mountains, near the village of Baligrod, Poland October 27, 2016. (Photo by Kacper Pempel/Reuters)

In a photo taken on November 27, 2016 a female traffic police officer directs traffic on a road in Pyongyang. Believed to be hand-picked for their looks, Pyongyang's female traffic police are a familiar sight at intersections around the capital, where traffic volumes have noticeably increased in recent years. (Photo by Ed Jones/AFP Photo)

Lowry Park Zoo elephants Matjeka, 23, and her 1-year-old daughter, Mavi, apply a liberal coating of “sunscreen” to themselves in a clay mud wallow at the park Tuesday, August 12, 2014, in Tampa, Fla., on the park's first observation of World Elephant Day to raise awareness of the wild African elephant crisis. “Elephants are prone to being sunburned”, said associate curator Chris Massaro. “What they need is lot of mud or clay to roll around in and cover up their skin so it will protect it from the sun”. (Photo by Cherie Diez/AP Photo/The Tampa Bay Times)

Xiren Wang, Lili Wat, and Sitong Chen join the pageant’s opening routine, dancing to “The Boys”, a song by K-Pop group «Girls’ Generation». While the women come from a range of professional backgrounds – including economics, nursing, and acting – every contestant is looking for her big break into the entertainment industry. Most contestants said they would prefer to have a career in the U.S. but would go wherever the opportunity lies. (Photo and caption by John Brecher/Sahra Vang Nguyen/NBC News)

A poster for the IMAX presentation of “The Hunger Games: Catching Fire” (left), and a teaser poster for “The Hunger Games: Mockingjay, Part I”, both created by the Los Angeles-based design firm IGNITION. Both are nominated for the 2014 Key Art Awards in the category of Theatrical Domestic One-Sheet. The Hollywood Reporter's annual competition for the best in film and TV advertising honors some of the most creative imagery used in movie posters. Here is a selection of some of this year's nominees. (Photo by Key Art Awards 2014)

“Hippo Chase”. As we approached the camp the Selinda Reserve of northern Botswana our boat passed by a hippo resting in the water. I turned around to look back at the boat's wake and saw the hippo charging after us! The hippo must've been tired from an all-nighter because he was angry. He rose way up out of the water three times trying to chase our boat! He was coming at us with such force that he created a wake of his own. Photo location: Selinda Reserve of northern Botswana. (Photo and caption by Curtis Simmons/National Geographic Photo Contest)

A Ford Motor Company 1954 V8 model car parked in a garage in the village of Quivican, south of Havana, October 11, 2009. (Photo by Desmond Boylan/Reuters)