  Terrestrial Gamma-Ray Flashes (TGFs) are very short bursts of high energy
photons and electrons originating in Earth's atmosphere. We present here a
localization study of TGFs carried out at gamma-ray energies above 20 MeV based
on an innovative event selection method. We use the AGILE satellite Silicon
Tracker data that for the first time have been correlated with TGFs detected by
the AGILE Mini-Calorimeter. We detect 8 TGFs with gamma-ray photons of energies
above 20 MeV localized by the AGILE gamma-ray imager with an accuracy of 5-10
degrees at 50 MeV. Remarkably, all TGF-associated gamma rays are compatible
with a terrestrial production site closer to the sub-satellite point than 400
km. Considering that our gamma rays reach the AGILE satellite at 540 km
altitude with limited scattering or attenuation, our measurements provide the
first precise direct localization of TGFs from space.
