Nuclear Explosions and Magnetic Storms: Decoding Celestial Flashes
Old photographic plates from a 1950s sky survey held a detective mystery: mysterious flashes kept appearing on them. The first clue — the flashes coincided with days of atmospheric nuclear tests. The second clue — the Earth's magnetic field: the stronger the storm raged, the rarer the spots.
It was as if the suspect only came out in calm weather.