The Jet Propulsion Lab team's RoboSimian robot turns on a valve at a simulated disaster-response course during day one of the Defense Advanced Research Projects Agency (DARPA) Robotics Challenge finals in Pomona, California, June 5, 2015. (Photo by David McNew/Reuters)

A green iguana, or American iguana sits on an Aldabra giant tortoise, the largest tortoise of the world, in their enclosure at the zoo park of Lille, northern France, on February 11, 2019. (Photo by Philippe Huguen/AFP Photo)

A reveler in costume laughs during the “Cordao do Boitata” street party in Rio de Janeiro, Brazil, Sunday, February 24, 2019, one of the many parades before the official start of Carnival on March 1. (Photo by Leo Correa/AP Photo)

The cruise ship Viking Sky as it drifts after sending a Mayday signal because of engine failure in windy conditions near Hustadvika, off the west coast of Norway, Saturday March 23, 2019. The Viking Sky is forced to evacuate its estimated 1,300 passengers. (Photo by Odd Roar Lange/NTB Scanpix via AP Photo)

A young woman takes pictures of the city with her mobile phone, from the glass-floor observation platform, in the Oriental Pearl Tower, in the financial district of Shanghai, on May 9, 2019. (Photo by Hector Retamal/AFP Photo)

Members of the U.S. Army's Golden Knights parachute team perform during the Bethpage Air Show as part of a Memorial Day event at Jones Beach on Long Island, New York, U.S., May 25, 2019. (Photo by Johnny Milano/Reuters)

Prime Minister Theresa May meets Russian President Vladimir Putin during the G20 summit in Osaka, Japan on June 28, 2019. (Photo by Stefan Rousseau/PA Images via Getty Images)

A man with henna-dyed hair rests on a road near the port area in Karachi, Pakistan on July 3, 2019. (Photo by Akhtar Soomro/Reuters)