Galactic Cosmic Radiation
(GCR) Come from outside the solar system but generally from within our Milky Way galaxy. It consists of ionized atoms ranging from a single proton up to an uranium nucleus. The Earth's magnetic field provides shielding for spacecraft from galactic cosmic radiation. However, cosmic rays have free access over the polar regions where the magnetic field lines are open to interplanetary space.
Solar particle Events
Solar particle events are injections of energetic electrons, protons, alpha particles, and heavier particles into interplanetary space. These particles are accelerated to near relativistic speeds by the interplanetary shock waves which precede fast coronal mass ejections and which exist in the vicinity of solar flare sites.
Geomanagretic Trapped Radiation
The rotation of the Earth's molten iron core creates electric currents that produce magnetic field lines around the Earth similar to those associated with an ordinary bar magnet. This magnetic field extends several thousand kilometers out from the surface of the Earth.