Accelerators in the sky

The author surveys the large body of evidence showing that there are very efficient mechanisms capable of accelerating particles to high energies under very different astrophysical conditions. Without going very far out into space we already know that there are several circumstances in the solar system whereby fast particles are accelerated with great efficiency (10/50%), for instance, in the solar flares, in the earth magnetosphere, in the atmosphere of Jupiter, etc. However, those circumstances are considered here whereby huge amounts of relativistic and ultra-relativistic particles such as one finds in (a) cosmic rays, (b) supernova remnants and (c) radio galaxies and quasars are produced. (0 refs).