The US accidentally discovers how to use the atmosphere as a spy

The US Agency for Advanced Defense Research Projects, better known as DARPA, which is responsible for developing new technologies, has made an unexpected discovery. With their Atmo Sense project, they demonstrated that wave propagation models were capable of detecting terrestrial, aerial or space events of interest to national security. This allows us to accurately locate invisible threats anywhere in the world, from earthquakes, space reentranc…