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)

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)

Penitentiary system guards carry an inmate with symptoms related to the novel coronavirus at the COVID-19 unit of San Juan de Dios hospital in Guatemala City on July 13, 2020. (Photo by Johan Ordonez/AFP Photo)

Children playing on Walled City rooftop in Hong Kong, 1989. The lack of formal governance in the Walled City led to challenges, but it also fostered a unique system of informal social order. (Photo by Greg Girard/The Guardian)

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)

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)

Microsoft co-founder Paul Allen has spent the last six years working on a giant aircraft capable of launching rockets to space. Today, his company Stratolaunch Systems literally rolled that plane out of its hangar in the Mojave Desert for the first time ever.

is a concentrated solar power plant with a molten salt heat storage system. It is located within the city limits of Fuentes de Andalucía in the province of Seville, Spain.