A man dressed as Ironman takes a seat in the cafeteria on the second day of the London Super Comic Convention at the ExCel centre in east London, on March 15, 2015. (Photo by Justin Tallis/AFP Photo)

The shadow of a partial eclipse is cast on to the cheek of a student on the roof of the Jana Dlugosza Academy in Czestochowa, Poland March 20, 2015. (Photo by Grzegorz Skowronek/Reuters/Agencja Gazeta)

Hooded penitents from “La Borriquita” brotherhood take part during a Holy Week procession in Cordoba, Spain, Sunday, March 29, 2015. Hundreds of processions take place throughout Spain during the Easter Holy Week. (Photo by Manu Fernandez/AP Photo)

The waning moon is setting over the mountain “Les Cornettes de Bise” located at the border of the Haute-Savoie and the Valais canton of Switzerland in the Chablais Alps, photographed from Glutieres, January 7, 2015. (Photo by Anthony Anex/EPA)

Rihanna attends the Balmain show as part of the Paris Fashion Week Womenswear Fall/Winter 2014-2015 on February 27, 2014 in Paris, France. (Photo by Dennis Leupold/The Guardian)

A police officer sprinkles colored powder onto a police dog at Nepal's Central Police Dog Training School during a dog worship day as part of the Diwali festival, also known as Tihar Festival, in Kathmandu, Nepal, 10 November 2015. The Tihar festival is the second major festival for Nepalese Hindus and this year is held from 10 November 2015. (Photo by Narendra Shrestha/EPA)

Alexo Carmona, 2, looks at Coco, a two-year-old pony, in downtown Havana, in this March 6, 2015 file photo. Nearly a quarter of a million people follow the Reuters Instagram account – and it's still growing fast. To mark the mid-point of 2015, Reuters has compiled the twenty most-liked pictures so far. This picture was 20th most popular. (Photo by Alexandre Meneghini/Reuters)