A PETA (People for the Ethical Treatment of Animals) activist with her body painted promotes veganism in Bangkok April 21, 2016. (Photo by Jorge Silva/Reuters)

In this Thursday, April 16, 2015 photo provided by Robert MacFarlane, a raccoon climbs up a skyscraper in downtown Toronto. Social media was abuzz Thursday with the photo of the raccoon peering from between the metallic rungs of a crane 58 stories high. (Photo by Robert MacFarlane)

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)

A soldier poses with a Hythe Mk III Gun Camera during training activities at Ellington Field, Houston, Texas in April of 1918. The Mk III, built to match the size, handling, and weight of a Lewis Gun, was used to train aerial gunners, recording a photograph when the trigger was pulled, for later review, when an instructor could coach trainees on better aiming strategies. (Photo by Harry Kidd/WWI Army Signal Corps Photograph Collection via The Atlantic)

Teachers carry children away from Briarwood Elementary school after the tornado destroyed the school in south Oklahoma City. (Photo by Paul Hellstern/The Oklahoman)

An x-ray of a woman drinking, taken by British artist and photographer Hugh Turvey in London, England. (Photo by Hugh Turvey/SPL/Barcroft Media)

Women playing in the street as the snow falls on Johannesburg for the first time in seventeen years. (Photo by Keystone/Getty Images). 1st September 1962