Punk protest band p*ssy Riot member Maria Alyokhina is detained by police at a protest in central Moscow February 24, 2014. Russian riot police detained over a hundred protesters, including two members of p*ssy Riot, on Monday at a Moscow courthouse where seven opponents of President Vladimir Putin were jailed from two and a half to four years over a demonstration that turned violent. (Photo by Maxim Shemetov/Reuters)

People protect themselves behind a trash can as anti-riot olice fires water cannon to disperse thousands of people demonstrating following the death of Berkin Elvan, a teenage boy wounded in mass anti-government demonstrations last year, on March 11, 2014 near the Middle East Technical University (ODTU) in Ankara. Elvan's story – he spent 269 days in a coma – gripped the nation and became a symbol of the heavy-handed tactics used by police to reign in the biggest demonstrations against Prime Minister Recep Tayyip Erdogan since he came to power in 2003. (Photo by Adem Altan/AFP Photo)

An image produced by the Hubble telescope of the perfectly “edge-on” galaxy, or NGC 4013, March 1, 2001. This new Hubble picture reveals, with great detail, huge clouds of dust and gas extending along, as well as far above, the galaxy's main disk. NGC 4013 is a spiral galaxy, similar to the Milky Way, lying some 55 million light-years from Earth in the direction of the constellation Ursa Major. Viewed face-on, it would look like a nearly circular pinwheel, but NGC 4013 happens to be seen edge-on from our vantage point. Even at 55 million light-years, the galaxy is larger than Hubble's field of view, and the image shows only a little more than half of the object, albeit with unprecedented detail. (Photo Courtesy of NASA/Newsmakers)

A security guard walks past a giant Doctor Who poster at the “Doctor Who 50th Celebration” event in the ExCeL centre on November 22, 2013 in London, England. The sold-out three day event in the ExCeL London convention centre celebrates 50 years of the show which has seen 11 actors play the role of Doctor Who and receives a worldwide cult following. (Photo by Oli Scarff/Getty Images)

A handout photograph provided by Brian Kubicki of Costa Rican Amphibian Research Center on 26 April 2016 shows a “Crystal frog”, Hyalinobatrachium dianae (H. diane). This frog was discovered by US biologist Brian Kubicki and Costa Ricans Stanley Salazar and Robert Puschendorf in a rainy forest of Costa Rican caribbean after 40 years without notice of any new example of this kind. (Photo by Brian Kubicki/EPA/Costa Rican Amphibian Research Center)

In this April 23, 2015 photo, friends Jia Haixia, left, and Jia Wenqi work to plant a tree in a field in Yeli village near Shijiazhuang city in northern China's Hebei province. For the past 13 years, Jia Wenqi, who has no arms, and Jia Haixia, who is blind, have worked together to plant and water more than 12,000 trees near their village. (Photo by Helene Franchineau/AP Photo)

“Environmental Migrants: The Last Illusion” by photographer Alessandro Grassani, documents the life of people in Kenya, Mongolia and Bangladesh who migrate to escape environmental stresses to the city of their own countries in hopes for a better life. Here: Asia, Mongolia, March 27, 2011. A view of Ulaan Baator over the shoulder of a slumbering drunk. Alcoholism is a huge problem in the city, home to almost half of Mongolia's people. The capital's population has doubled in the past two years. High levels of unemployment and poverty await herders who abandon rural areas and arrive in the city, illiterate and untrained in any skills necessary for urban jobs. (Photo by Alessandro Grassani)

A Nepalese Hindu devotee bathes in the Bagmati River on her way to the Pashupatinath Temple to offer prayers to Lord Shiva, Hindu god of destruction during Shravan festivities in Sundarijal, on the outskirts of Kathmandu on August 3, 2015. According to the Nepali calendar, Shravan is considered the holiest month of the year with each Monday of the month known as Shravan Somvar when worshippers offer prayers for a happy and prosperous life. (Photo by Prakash Mathema/AFP Photo)