What is the main reason it is difficult to pinpoint the exact source of a detected cosmic ray particle?

Answer

Their paths are severely deflected and randomized by magnetic fields in space

Because cosmic rays are electrically charged particles, they interact with magnetic fields in space, causing their trajectories to become twisted and randomized, making tracing their precise origin difficult compared to straight-traveling photons.

What is the main reason it is difficult to pinpoint the exact source of a detected cosmic ray particle?
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