A man wearing an illuminated atmospheric diving suit as part of an installation titled “What Lies Beneath” looks at members of the public during the Vivid Sydney festival of light and sound in Sydney, Australia, May 26, 2017. (Photo by Steven Saphore/Reuters)

The possible surface of TRAPPIST-1f, one of seven newly discovered planets in the TRAPPIST-1 system that scientists using the Spitzer Space Telescope and ground based telescopes have discovered. (Photo by Reuters/NASA/JPL-Caltech)

A student protester throws a stone against a riot police vehicle during a demonstration to demand changes in the education system in Santiago, Chile, April 21, 2016. (Photo by Ivan Alvarado/Reuters)

“Pantsir-S1 (NATO reporting name SA-22 Greyhound) is a combined short to medium range surface-to-air missile and anti-aircraft artillery weapon system produced by KBP of Tula, Russia. The system is a further development of SA-19/SA-N-11 and represents the latest air defence technology by using phased-array radars for both target acquisition and tracking”. – Wikipedia

Photo: Test of the surface-to-air missile Pantsir-S rocket and gun system in the conditions of the Polar region on the range “Pemba” near Vorkuta, approximately on October 20 2012. According to the statement of military, during doctrines five cruise missiles from five were destroyed. (Photo by Alexey Reznichenko)

Demonstrators perform a dance in front of riot policemen during a march called by students to request changes in the education system in Santiago, Chile September 5, 2017. (Photo by Ivan Alvarado/Reuters)

Burmese children attend classes at a government run school December 14, 2011 in Waw township, Myanmar. The education system is based on the United Kingdom's system, after nearly a century of British and Christian presences in Burma. (Photo by Paula Bronstein/Getty Images)

An Israeli missile is launched from the Iron Dome missile system in response to a rocket launch from the nearby Palestinian Gaza Strip, on March 12, 2012 near Ashdod, Israel. (Photo by Uriel Sinai/Getty Images)

A protester reacts as police use water cannon during a demonstration to demand changes in the Chilean education system in Santiago, Chile June 25, 2015. (Photo by Ueslei Marcelino/Reuters)