Gregory Benford, a scientist at the University of California, and Raymond Protheroe, a scientist at the University of Adelaide, have hypothesized that cosmic rays are able to reach Earth due to energy provided by magnetic cocoons.

Magnetic cocoons are supergiant magnetized cocoons of plasma or charged particles that exist in outer space. They are carved out by "jets" stabbing out from extremely massive black holes located at the heart of active galaxies.

According to Benford and Protheroe, cosmic rays should theoretically run out of steam before even reaching the Earth. That is, until they come into contact with magnetic cocoons.

Benford and Protheroe went on to explain that the magnetic fields of these cocoons tends to decay slowly over billions of years. This process induces an electrical field which is strong enough to accelerate cosmic rays to ultra-high energies, thus enabling the cosmic rays to reach the Earth. Cosmic rays pass through many such fields en route to Earth.

Raymond Protheroe pointed out that the magnetic cocoons store truly vast amounts of energy in their electrical fields. How vast, you may ask? Vast enough to accelerate cosmic rays to within a whisker of the speed of light. It also looks like these cocoons will be powering up cosmic rays for a long, long time to come, so if you're an aspiring astronaut, keep those deflector shields handy.