A female sniper of the Syrian Democratic Forces (SDF) monitors the area during a celebration at the iconic Al- Naim square in Raqa on October 19, 2017, after retaking the city from Islamic State (IS) group fighters. The SDF fighters flushed jihadist holdouts from Raqa' s main hospital and municipal stadium, wrapping up a more than four- month offensive against what used to be the inner sanctum of IS' s self- proclaimed “caliphate”. (Photo by Bulent Kilic/AFP Photo)

The Lake of Lights at Talkin Tarn lake near Brampton in Cumbria, England on October 22, 2017 – where hundreds of lights in the surrounding woodland represent a cherished memory of a relative friend or loved one no longer with us. (Photo by Owen Humphreys/PA Images via Getty Images)

Yippie leader Jerry Rubin, barred on December 4, from House Un-American Activities subcommittee hearing, aims a toy gun in “self defense” outside the Washington hearing room on December 5, 1969. Rubin showed up in his Santa Clause suit because he believed it was typical of the committee which, he said, “is a total circus”. (Photo by Bob Daugherty/AP Photo)

A follower of the Afro-Brazilian religion Umbanda pays tribute for Iemanja, goddess of the sea, in Copacabana Beach in Rio de Janeiro, Brazil December 29, 2017. Hundreds of practitioners of Brazil's Afro-Brazilian Candomble and Umbanda faiths have gathered at Rio de Janeiro's Copacabana beach to honor Yemanja. Worshippers were mostly dressed in white as they launched their offerings to Iemanja: small boats with flowers and bowls with candles and fruits. (Photo by Ricardo Moraes/Reuters)

Spacewalker Mark Vande Hei took his own photograph during the first spacewalk of 2018, on January 23, 2018. These sky-high pictures are better known as “space-selfies”. (Photo by Mark Vande Hei/NASA)

Indonesian students go to school via a makeshift suspension bridge in Ngemplak, Boyolali regency, Indonesia on November 15, 2017. The lack of access to roads makes students every day to cross the dangerous waterways to go to school. (Photo by Arief Setiadi/Pacific Press/Barcroft Images)

Concertgoers dance at the Coachella Valley Music and Arts Festival in Indio, California, U.S., April 15, 2018. Coachella became one of the world' s premier music festivals not only for the A- list performers. The two- weekend party in the California desert has become a major event in its own right for the fashion. While designers have heavily marketed their brands to Coachella, the fans who draw the most notice often do so by embracing their own sartorial flair, driven by a sense of innovation and, among revelers in the searing heat, of inhibition. (Photo by Mario Anzuoni/Reuters)

Aerial photo taken on April 20, 2018 shows the view of advection fog above Qingdao, a coastal city in east China' s Shandong Province. (Photo by Lu Hui/Xinhua News Agency/Eyevine)