A wide range of topics are covered, ranging from supernovae to active galactic nuclei, cosmic gamma rays to neutrinos and dark matter. The basic emphasis is on physics / astrophysics and experimental / observational techniques, scientific implications of current results, and prospects for future advances. The fields surveyed are in rapid development and the exploration of our high energy universe is proceeding rapidly, with exciting new discoveries. What unifies much of the new data is the idea of particle acceleration to enormous energies and the subsequent interactions of the particles with the local medium. It this focus that makes the book both timely and an important contribution to the field.