Giant panda Meng Meng plays on a tree at a Siberian tiger-breeding base in Changchun, China on December 10, 2015. (Photo by Xu Chang/Xinhua Press/Corbis)

Tomomi Ota pushes a trolley loaded with her humanoid robot Pepper as she crosses a street in Omotesando shopping district in Tokyo, Japan, 24 March 2016. Telecommunications and mobile phone carrier SoftBank Corp. opened a robot-staffed store where 10 Pepper humanoid robots welcome customers looking to buy a mobile phone. The store will be opened until 30 March 2016. (Photo by Franck Robichon/EPA)

A man is silhouetted as he stands on a walkway in the sky lobby at the Chancellery, the seat of German Chancellor Angela Merkel (not pictured) in Berlin, May 7, 2014. (Photo by Thomas Peter/Reuters)

An infrared portrait from NASA's Spitzer Space Telescope which shows generations of stars is seen in this undated NASA handout image released February 14, 2013. In this wispy star-forming region, called W5, the oldest stars can be seen as blue dots in the centers of the two hollow cavities (other blue dots are background and foreground stars not associated with the region). Red shows heated dust that pervades the region's cavities, while green highlights dense clouds. (Photo by NASA/Reuters/JPL-Caltech/Harvard-Smithsonian/Handout)

Blossoms and dust are blown by the wind as Jasmin Ricks, left, and her sister, Jessica Ricks, center, take in the cherry blossoms near the Tidal Basin in Washington on April 12, 2018. (Photo by Matt McClain/The Washington Post)

Pallas' s cat kittens with theit mother in an enclosure at the Novosibirsk Zoo, Novosibirsk, Russia on July 11, 2018. Pallas' s cat, also known as manul, is a small wild cat native to montane steppes of the Central Asia and listed as an endangered species. (Photo by Kirill Kukhmar/TASS)

In this Friday, November 30, 2018 handout photo released by Raindrop Media, Bollywood actress Priyanka Chopra and Nick Jonas celebrate during a mehendi ceremony, a day before their wedding, at Umaid Bhawan in Jodhpur, India. (Photo by Raindrop Media via AP Photo)

One of the invited tattoo artists, Tom Storm, works on the arm of Kerrie Hibbert at the 2017 Tattoo Collective event at the Old Truman Brewery in London, England on February 17, 2017. (Photo by PA Wire)