Author(s): L. B. Wilson, III, D. G. Sibeck, D. L. Turner, A. Osmane, D. Caprioli, and V. Angelopoulos
The THEMIS spacecraft has observed surprisingly high velocity electrons upstream of where the solar wind collides with Earth’s magnetosphere. Current theories of ion acceleration in foreshock disturbances cannot account for the high relativistic energies of these electrons.
[Phys. Rev. Lett. 117, 215101] Published Mon Nov 14, 2016