Yerevan residents celebrate Armenian Prime Minister's Serzh Sargsyan's resignation in Yerevan, Armenia, Monday, April 23, 2018. Sargsyan resigned unexpectedly on Monday, an apparent move to bring to an end massive anti-government protests. (Photo by Amos Chapple/RFE/RL)

The moon is seen in its waxing gibbous stage as it rises behind the helicopter from the original Batman television show, which people can ride at the New Jersey State Fair, Saturday, June 22, 2013, in East Rutherford, N.J. The moon, which will reach its full stage on Sunday, is expected to be 13.5 percent closer to earth during a phenomenon known as supermoon. (Photo by Julio Cortez/AP Photo)

Female pilot Anna climbs out the cockpit of Japanese electronics company Suidobashi Heavy Industry's newly unveiled robot “Kuratas” at the Wonder Festival in Chiba, suburban Tokyo on July 29, 2012. The “Kuratas” robot, which will go on sale with a price tag of one million USD, measures four meters in height, weighs four tons and has four wheeled legs that can either be controlled remotely through the 3G network or by a human seated within the cockpit. (Photo by Yoshikazu Tsuno/AFP Photo)

The sculpture “It Takes Two to Tango” by Scottish sculptor David Mach is seen in front of the headquarters of the CMA-CGM shipping company office tower in the port of Marseille, France, March 15, 2016. (Photo by Jean-Paul Pelissier/Reuters)

A boy rides on a snow wagon towed by a robot dressed as a Teddy bear, which only moves forward by moving its legs, during the Ice and snow carnival at Taoranting park in Beijing February 9, 2015. (Photo by Kim Kyung-Hoon/Reuters)

A visitor looks at a creation by Russian artist Irina Nakhova presented at the Russia's pavilion during the 56th International Art Exhibition (Biennale d'Arte) titled “All the Worlds Futures” on May 5, 2015 in Venice. (Photo by Gabriel Bouys/AFP Photo)

A competitor wearing a kilt and standing on a barrel throws a bowling ball between her legs during the “Brigaball” contest at the annual Bundanoon Highland Gathering, showcasing traditional Scottish events, held in the town of Bundanoon, located southwest of Sydney, April 9, 2016. (Photo by David Gray/Reuters)

A U.S. soccer fan pretends that Uruguay's soccer striker Luis Suarez is biting him as he takes a selfie next to an Adidas advertisement featuring Suarez near Copacabana beach in Rio de Janeiro, Brazil, Thursday, June 26, 2014. FIFA banned Suarez from all football activities for four months on Thursday for biting an opponent at the World Cup, a punishment that rules him out of the rest of the tournament. (Photo by Matt Dunham/AP Photo)