I really thought someone (US?) had technology (satellites) that could pinpoint radiation sources, even of this magnitude
I had the same thought briefly, but then thought more about it. These are high energy particles. You might remember the article about cosmic rays that sometimes cause a single bit flip in a videogame, and that there is no easy way to shield against it. That makes satellite imaging difficult, because how do you focus some sort of lens, if the particles go right thru everything? You might detect that a cosmic ray or io…
> The LAT detects gamma rays by using Einstein’s famous E = mc2 equation in a technique known as pair production. When a gamma ray, which is pure energy, slams into a layer of tungsten in the detector, it can create a pair of subatomic particles (an electron and its antimatter counterpart, a positron). The direction of the incoming gamma ray is determined by projecting the direction of these particles back to their source using several layers of high-precision silicon tracking detectors.