Mount Sinabung volcano erupts, as seen from Tiga Pancur village, Karo Regency in Indonesia's North Sumatra province, in this October 8, 2014 file photo. (Photo by Y. T. Haryono/Reuters)

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 fox runs out onto the pitch before the start of the second half. Celtic League 2012/13, Round 19, Leinster v Ulster, RDS, Ballsbridge, Dublin, March 30, 2013. (Photo by Paul Mohan)

“Centuries ago, Inuit hunted the bowhead whale. At that time, whale hunting undoubtedly was part of a complex and very important ritual, if only because of the size of the catch. The position that the ancestors of today's Inuit occupied in the living world involved a relationship with the spirit that inhabited each animal but also their species”. (Photo by Robert Frechette/2014 Sony World Photography Awards)

“Show us our butts! Mucawana tribe – Angola. In Soba village, the Muhacaona (Mucawana) tribe, perhaps the best place i have visited. They use cow dung and fat to make this so nice haircut, and love the beads. They asked me to make pictures of their backs... and butts to see on the camera screen if everything was perfect!”. (Photo and comments by Eric Lafforgue)

An Indian Army soldier marches next to a tableau during the Republic Day parade in New Delhi, India, January 26, 2016. India celebrated its Republic Day Tuesday, highlighted by a march by different branches of the military as well as a display of arms and missiles. (Photo by Adnan Abidi/Reuters)

Students dance in the hallway during a break at Moscow State Academy of Choreography in Moscow, Russia 03 March 2016. Moscow State Academy of Choreography is the oldest institution in Moscow which teaches Ballet arts not only Russian citizens, but also representatives from more than 20 countries. (Photo by Yuri Kochetkov/EPA)