http://www.newsweek.com/darpa-muons-subatomic-particles-scan-us-military-1727620

The United States' military has announced it is seeking to create powerful subatomic particle beams that would enable personnel to "see" through walls tens of yards thick and even peer deep underground.

Using radiation or particles to see through objects is something scientists have done for decades and across a variety of industries. Commercial aviation has made use of neutrons and gamma rays to scan the interiors of airfreight containers for illicit materials, and x-ray scans are widely used in healthcare to see the bone structure of our bodies.