The Northern Lights glow green in a spectacular light show above a field of trees frozen solid with snow. (Photo by Jaak Sarv/Solent News & Photo Agency)

A truck carrying iron ore moves along a road at the Fortescue Metals Group (FMG) Christmas Creek iron ore mine located south of Port Hedland in the Pilbara region of Western Australia, November 17, 2015. (Photo by Jim Regan/Reuters)

North Korean leader Kim Jong Un is hugged by children during his visit to Samjiyon County in this undated photo released by North Korea's Korean Central News Agency (KCNA) in Pyongyang November 28, 2016. (Photo by Reuters/KCNA)

Goat herder Dana McGregor's goats Pismo, left, and Goatee surf at San Onofre State Beach, Calif, on July 11, 2012. McGregor started taking Pismo's mother Goatee to the beach, and it wasn't long before she was on a surfboard. When Pismo was born, McGregor put her on a board too, and she was a natural, he says. (Photo by Rod Veal/The Orange County Register via AP)

Ivy Levan is seen on the Universal Music Group stage at the SXSW 2015 Experience, Friday, March 20, 2015, in Austin, Texas. (Photo by Jack Dempsey/Invision for Universal Music Group/AP Images)

A close up shows Ukraine's Hanna Ryzhykova leg breaking a hurdle before crashing out as she competes in the women's 400m hurdles heats during the European Athletics Championships at the Letzigrund stadium in Zurich on August 13, 2014. (Photo by Olivier Morin/AFP Photo)