Supporters of the presidential candidate Muhammadu Buhari and his All Progressive Congress hits with a motorbike another supporter during celebrations in Kano March 31, 2015. Nigeria's opposition APC declared an election victory on Tuesday for former military ruler Buhari and said Africa's most populous nation was witnessing history with its first democratic transfer of power. (Photo by Goran Tomasevic/Reuters)

A Uyghur boy sits atop a horse as he has his picture taken outside the Id Kah Mosque before the Eid holiday on July 28, 2014 in old Kashgar, Xinjiang Province, China. Nearly 100 people have been killed in unrest in the restive Xinjiang Province in the last week in what authorities say is terrorism but advocacy groups claim is a result of a government crackdown to silence opposition to its policies. China's Muslim Uyghur ethnic group faces cultural and religious restrictions by the Chinese government. Beijing says it is investing heavily in the Xinjiang region but Uyghurs are increasingly dissatisfied with the influx of Han Chinese and uneven economic development. (Photo by Kevin Frayer/Getty Images)

A model showcases designs on the runway at MGPIN 2015 Mao Geping Makeup Trends Launch show during Mercedes-Benz China Fashion Week Spring/Summer 2015 at Beijing Hotel on October 27, 2014 in Beijing, China. (Photo by Feng Li/Getty Images)

Cast members Ryan Hansen, Kristen Bell, and Jason Dohring (L-R) pose at the premiere of “Veronica Mars” in Hollywood, California in this March 12, 2014 file photo. (Photo by Mario Anzuoni/Reuters)

Students receive a group punishment during a military-style close-order drill class at the Qide Education Center in Beijing February 19, 2014. The Qide Education Center is a military-style boot camp which offers treatment for internet addiction. As growing numbers of young people in China immerse themselves in the cyber world, spending hours playing games online, worried parents are increasingly turning to boot camps to crush addiction. Military-style boot camps, designed to wean young people off their addiction to the internet, number as many as 250 in China alone. (Photo by Kim Kyung-Hoon/Reuters)

NASA says it could be another 20 years before humans touch down on Mars, but in a sense, the Mars Society has been exploring the red planet for more than a decade – in Utah. Photo: Csilla Orgel, a geologist of Crew 125 EuroMoonMars B mission, makes her way back to the Mars Desert Research Station (MDRS) in the Utah desert March 3, 2013. The MDRS aims to investigate the feasibility of a human exploration of Mars and uses the Utah desert's Mars-like terrain to simulate working conditions on the red planet. Scientists, students and enthusiasts work together developing field tactics and studying the terrain. All outdoor exploration is done wearing simulated spacesuits and carrying air supply packs and crews live together in a small communication base with limited amounts of electricity, food, oxygen and water. Everything needed to survive must be produced, fixed and replaced on site. (Photo by Jim Urquhart/Reuters)

A general view shows the Krasnoyarsk hydro-electric power station on the Yenisei River near the Siberian city of Krasnoyarsk, Russia, January 13, 2016. The power plant, owned by EuroSibEnergo company, part of En+ Group, with a generating capacity of 6,000 megawatt (MW), has a ferro-concrete dam 124-metres high and 1065-metres long and is the second largest Russian hydroelectric power station. About 85% of the energy generated is intended for the Rusal Krasnoyarsk aluminium smelter, according to representatives of the power station. (Photo by Ilya Naymushin/Reuters)

A worker cleans a dragon ahead of the upcoming Chinese Lunar New Year celebrations at the Boen Tek Bio temple in Tangerang, Banten province, Indonesia February 1, 2016. (Photo by Reuters/Beawiharta)