Participants climb over a wall at the “Tough Mudder” endurance event series in Arnsberg September 6, 2014. Competitors who took part in the endurance event saw themselves having to overcome various military style obstacles. (Photo by Ina Fassbender/Reuters)

Spectators cheer as the United Launch Alliance Delta 4-Heavy rocket, with NASA's Orion spacecraft mounted atop, lifts off from the Air Force Station, December 5, 2014, in Cape Canaveral, Fla. (Photo by Smiley N. Pool/AP Photo/Houston Chronicle)

The “EMIEW3” robot (R) demonstrates communicating with a visitor during a press preview in Tokyo on April 8, 2016. Japanese electronics giant Hitachi unveiled its humanoid customer service and guidance robot “EMIEW3” and “remote brain” robotics IT platform. (Photo by Toshifumi Kitamura/AFP Photo)

On the streets of Kunming, Yunnan Province, you can find odd couple – a dog and a cat who sits on his four-legged companion. They are Vantsay and Mimi. The owner of animals, a 42-year-old retired policeman Xu Jin is surprised with so strong friendship. “When I got the dog, and I began to take her for a walk, the cat became plaintive, – says the man. – So I bought a leash and began to take her too. Soon, however, the cat began to tire and quickly realized that it is much easier to ride on the back of a dog. ”

US Vogue’s top fashion editor works with photographers to inject style with sci-fi and fantasy. A new book, “Stoppers: Photographs from My Life at Vogue” by Phyllis Posnick and Vogue’s chief editor, Anna Wintour, highlights the results. Here: Surburban Woman #10, Mountainville, New York, August 2006. (Photo by Steven Klein)

Photographer Logan Zillmer took this photo of the harvest moon above a corn field as part of his “Traveler” series on Flickr. (Photo by Logan Zillmer)

Children stand in a boat at the banks of the polluted Yamuna River during a dust haze as they wait to give a ride to worshippers in New Delhi during World Environment Day June 5, 2010. (Photo by Reinhard Krause/Reuters)

In this photo posted on Twitter, Sunday, May 3, 2015, and provided by NASA, Italian astronaut Samantha Cristoforetti sips espresso from a cup designed for use in zero-gravity, on the International Space Station. Cristoforetti, the first Italian woman in space, fired up the first espresso machine in space, which uses small capsules, or pods, of espresso coffee. (Photo by AP Photo/NASA)