Black-headed gulls sit on pickets at a riverside in Tokyo, Japan, December 27, 2015. (Photo by Toru Hanai/Reuters)

A wide-angle view shows the ascent of the shuttle Challenger on January 28, 1986. In the seconds after ignition, the rocket engines' hot blast began the process of destruction. (Photo by NASA)

Female of pygmy hippopotamus called Malaya from Netherlands in zoo in Dvur Kralove nad Labem, Czech Republic, February 22, 2016. (Photo by David Tanecek/CTK via ZUMA Press)

A jogger runs on the bank of Donaukanal channel in central Vienna, Austria, September 5, 2016. (Photo by Heinz-Peter Bader/Reuters)

The moon rises behind the skyline and financial district in Toronto, November 25, 2015. (Photo by Mark Blinch/Reuters)

Cast member Ana de Armas poses during a photocall for the film “Hands of stone” out of competition at the 69th Cannes Film Festival in Cannes, France, May 16, 2016. (Photo by Regis Duvignau/Reuters)

Durga Kami, 68, who is studying tenth grade at Shree Kala Bhairab Higher Secondary School, walks with his classmate Sagar Thapa, 14, as they head to school in Syangja, Nepal, June 5, 2016. (Photo by Navesh Chitrakar/Reuters)

An emu runs to escape an approaching wildfire as it burns near Potero, California, U.S. June 20, 2016. (Photo by Mike Blake/Reuters)