Leaked Pentagon docs reveal advanced capabilities of Chinese spy balloon.

The shot-down Chinese spy balloon may have had synthetic aperture radar, which can see through certain objects, according to leaked Pentagon documents. Synthetic aperture radar is used by organizations like NASA and the European Space Agency to observe the earth's topography and is also used in war to spy on adversaries. The technology can "see" in the dark, as well as through clouds, smoke, soil, and rain. The documents also reveal that certain functions of the balloons are still unknown to US intelligence. A 21-year-old US National Guard airman was arrested in connection to the leaks.