Daimler AG Mercedes-Benz emblems stand ready for attachment to vehicles at the factory on January 30, 2012 in Sindelfingen, Germany. (Photo by Thomas Niedermueller/Getty Images)

Space Shuttle Atlantis lands at the Kennedy Space Center July 21, 2011 in Cape Canaveral, Florida. The landing brings to a close the 30-year era of the space shuttle program that began in 1981, and has included 135 missions. (Photo by Bill Ingalls/NASA via Getty Images)

Fighters from Germany take up position before competing in the Medieval Combat World Championship at Malbork Castle, northern Poland, April 30, 2015. Medieval combat is a full contact sport that revives the foot based tournament fighting of medieval Europe. Countries fight in refereed matches where the objective is to get the opposing team to the floor. There are also duels with polearms, swords and shields where the number of hits landed are scored. The fighters, both male and female, wear heavy armours and weapons, mostly replicas of authentic pieces, and fight following the knights code of conduct. According to organizers, 25 nations from 6 continents are taking part in the Championships, which started on April 30 and will go on until May 3. (Photo by Kacper Pempel/Reuters)

Twenty five life-size donkeys have been given pride of place in St Paul's Cathedral as part of an interfaith exhibition. They've been painted by Egyptian and Western artists, to show solidarity for the people of Egypt. Photo: Artist painted donkey statues are displayed in the “Caravan” exhibition on August 30, 2013 in London, England. (Photo by Peter Macdiarmid)

A man waits for Queen Beatrix's abdication ceremony outside the Royal Palace in Amsterdam April 30, 2013. The Netherlands is celebrating Queen's Day on Tuesday, which will also mark the abdication of Queen Beatrix and the investiture of her eldest son Willem-Alexander. (Photo by Paul Vreeker/Reuters)

A reveller takes part in an annual block party known as “Ceu na Terra” (Heaven on Earth), one of the many carnival parties to take place in the neighbourhoods of Rio de Janeiro, January 30, 2016. (Photo by Pilar Olivares/Reuters)

A wolf looks into the camera at the 30 km (19 miles) exclusion zone around the Chernobyl nuclear reactor in the abandoned village of Orevichi, Belarus, March 2, 2016. What happens to the environment when humans disappear? Thirty years after the Chernobyl nuclear disaster, booming populations of wolf, elk and other wildlife in the vast contaminated zone in Belarus and Ukraine provide a clue. (Photo by Vasily Fedosenko/Reuters)

A man sells traditional doll toys and sweets for children to celebrate the birthday of prophet Muhammad, also known as “mawlid al nabi”, which will fall next week, in a makeshift tent in Cairo, December 30, 2014. (Photo by Mohamed Abd El Ghany/Reuters)