There are satellites continuously monitoring the Earth for nuclear bursts. The latter have a characteristic double pulse of optical radiation, even in the case

There are satellites continuously monitoring the Earth for nuclear bursts. The latter have a characteristic double pulse of optical radiation, even in the case of a simple fission device. https://en.m.wikipedia.org/wiki/Nuclear_MASINT#Space-based_Nuclear_Energy_Detection https://en.m.wikipedia.org/wiki/Nuclear_MASINT#Space-based_N...