[lightedman]

Attention downvoters: Cosmic rays don't even make it through the atmosphere. They are depleted atomic nuclei which essentially smash into another atom and that's the end of it. Not even multi TeV cosmic rays, which are rare, get through. They never "pass straight through the Earth" either, that's pretty much reserved for neutrinos only. Particles with energies of about 10^18 eV arrive at the rate of about one per square kilometer of atmosphere per century. These very high energy cosmic rays are detected at the ground by looking for the secondary photons, electrons, muons and neutrons that shower large areas of the ground after the primary particle impacts the atmosphere.

Your ground-level bit flips are most likely caused by terrestrial radiation sources, not extra-terrestrial ones. This is just basic physics.