This photo released Saturday March 22, 2014 by Stichting Ambulance Wens or Ambulance Wish Foundation shows a giraffe at Blijdorp Zoo in Rotterdam giving a lick to terminally ill Mario Eijs on Wednesday March 19, 2014. The Stichting Ambulancewens “Ambulance Wish Foundation” offers transport for terminally ill patients who cannot walk to help fulfill a last wish, in Eijs' case to be taken to the Blijdorp Zoo in Rotterdam where he worked doing odd jobs for 25 years. Eijs, who has a mental handicap, is dying of a brain tumor and has difficulty walking or speaking. (Photo by AP Photo/Stichting Ambulance Wens)

This artist's scoreboard displays a fictional game between Mars and Earth, with Mars in the lead. It refers to the success rate of sending missions to Mars, both as orbiters and landers. Of the previous 39 missions targeted for Mars from around the world, 15 have been successes and 24 failures. For baseball fans, that's a batting average of .385. The United States has had 13 successes out of 18 attempts, or a “batting average” of .722. NASA's Curiosity rover, set to land on the Red Planet the evening of Aug. 5, 2012 PDT (morning of Aug. 6 EDT), will mark the United States' 19th attempt to tackle the challenge of Mars, and the world's 40th attempt. (Image by NASA/JPL-Caltech)

Actors dressed up as zombies walk around while posing for photos with passers-by in New York's Times Square on Friday, October 10, 2014 as a promotion for the season premiere of AMC's “The Walking Dead” this Sunday, October 12, 2014. (Photo by Gordon Donovan)

Rahma, 19 (L), pictured with her 10-year old brother Fahad on June 21, 2016 in Kano, Nigeria. A teenage girl born without limbs lives her life in a plastic bowl. Rahma Haruna is a bright, happy girl, despite suffering from a mystery condition that stopped her arms and legs developing properly – leaving her practically limbless and in constant pain. The 19-year- old, from Kano, Nigeria, was born a healthy baby but when she turned six months old her growth came to a sudden halt and she stopped hitting key development milestones. Rahma’s family do their best to provide her with a fulfilling life and transport her around the village in a plastic bowl. Rahma said: “They help me a lot. How do they? They give me anything I need”. Rahma died on 25 December 2016. (Photo by Sani Maikatanga/Barcroft Images)

German police officers take pictures as fireworks explode next to the Quadriga sculpture atop the Brandenburg gate during New Year celebrations in Berlin, Germany, January 1, 2017. (Photo by Fabrizio Bensch/Reuters)

A Thai visitor appears to be frightened by a life-size Velociraptor model also known as Raptor at the Dinosaur Planet theme park in Bangkok, Thailand, 25 March 2016. The 500 million baht (14 million US dollars or 12 million euro) theme park opening in the Thai capital aimed to attract more than 15,000 visitors a day featuring a chance to experience more than 200 dinosaurs from various species that are brought back to life. (Photo by Rungroj Yongrit/EPA)

Members of a propaganda troupe perform in a public square in Pyongyang on April 12, 2017. (Photo by Ed Jones/AFP Photo)

Internally displaced Syrians who fled Raqqa tie ropes for their tents in a camp in Manbij, Syria on April 6, 2017. (Photo by Rodi Said/Reuters)