NASA Goddard Space Flight Center John N. Bahcall Distinguished Lecture

ABSTRACT: Astronomical observations have demonstrated that cosmic sources are capable of accelerating protons and electrons to unexpectedly large energies with surprisingly high efficiency. Supernova remnants accelerate protons and electrons to nearly a thousand times the energy produced by terrestrial particle accelerators and unspecified, but cosmologically local sources achieve proton energies nearly a million times greater. Recent observations by the Auger, Chandra, Fermi, H.E.S.S., MAGIC and VERITAS telescopes will be briefly summarized and it will be argued that novel particle acceleration mechanisms are at work. Although there is no compelling evidence that new fundamental physics processes are needed, the observations do illustrate some remarkable features of higher energy physics.