For 10 points, name these particles which constantly bombard the Earth from outer space.
An anomalous type of these entities is produced by ionization via charge exchange followed by acceleration by the termination shock. High energy examples of these entities will interact with CMB photons to produce pions, lowering their energy to below the GZK cutoff. The flux of these entities is much smaller at lower energies than higher ones due to deflection by the solar wind. Carl Anderson conducted a 1932 study of these entities using a cloud chamber in which he discovered the positron. Around nine percent of these entities are alpha particles, while nearly ninety percent of them are protons. For 10 points, name these particles which constantly bombard the Earth from outer space.
An anomalous type of these entities is produced by ionization via charge exchange followed by acceleration by the termination shock.
cosmic rays