Relativistic electron acceleration at the bow shock of Jupiter and beyond (opens in new tab)

Collisionless shocks are ubiquitous in space plasmas throughout the Universe and are widely believed to be primary sites of cosmic ray acceleration1,2. The prevailing mechanism, diffusive shock acceleration, requires particles to repeatedly cross the shock front, gaining energy with each crossing. The maximum achievable energy is fundamentally constrained by the Hillas criterion, which relates the physical scale of the accelerator to the maximum particle energy3. However, the scarcity of dire...