Lightning strikes the Willis Tower (formerly Sears Tower) in downtown on June 12, 2013 in Chicago, Illinois. (Photo by Scott Olson/Getty Images)

Athletes in action during the international parachuting competition Mountain Gravity in Quinto, Switzerland, 27 August 2015. Some 200 participants from all over the world are expected to jump at the event running from 22 to 30 August 2015. (Photo by Samuel Golay/EPA)

Smoke rises during an explosion from an Israeli forces strike in Gaza City, Saturday, November 17, 2012. Israel bombarded the Hamas-ruled Gaza Strip with nearly 200 airstrikes early Saturday, the military said, widening a blistering assault on Gaza rocket operations by militants to include the prime minister's headquarters, a police compound and a vast network of smuggling tunnels. (Photo Hatem Moussa/AP Photo)

This photograph released by Indian Space Research Organization shows its polar satellite launch vehicle lifting off from a launch pad at the Satish Dhawan Space Centre in Sriharikota, India, Wednesday, February 15, 2017. India's space agency said it successfully launched more than 100 foreign nano satellites into orbit Wednesday aboard a single rocket.(Photo by Indian Space Research Organization via AP Photo)

A student shouts slogans against Venezuelan President Nicola Maduro during a protest on the main highway in Caracas on March 30, 2017. Venezuela' s Supreme Court took over legislative powers Wednesday from the opposition- majority National Assembly, whose speaker accused leftist President Nicolas Maduro of staging a “coup”. (Photo by Juan Barreto/AFP Photo)

A man presents a self-made robot that local media reported is able to carry a person, in Heihe, Heilongjiang province, China, April 5, 2017. (Photo by Reuters/China Daily)

Performers of circus company Circa perform during a photocall for the Edinburgh Festival Fringe on Calton Hill on August 1, 2017 in Edinburgh, United Kingdom. (Photo by Murdo MacLeod/The Guardian)

Uniformed participant dance during a mass rally and parade in the capital's main ceremonial square, a day after the ruling party wrapped up its first congress in 36 years by elevating him to party chairman, in Pyongyang, North Korea, May 10, 2016. (Photo by Damir Sagolj/Reuters)