Simultaneous Observations of Solar Protons Inside and Outside the Magnetosphere

S. M. Krimigis; J. A. Van Allen; T. P. Armstrong

doi:10.1103/PhysRevLett.18.1204

Simultaneous Observations of Solar Protons Inside and Outside the Magnetosphere

S. M. Krimigis, J. A. Van Allen, and T. P. Armstrong

Phys. Rev. Lett. 18, 1204 – Published 26 June 1967

Abstract

Simultaneous observations of low-energy (∼0.5 MeV) protons emitted in a solar flare of 7 July 1966 were made with detectors on board the earth satellites Explorer 33 and Injun IV, located outside and inside the earth's magnetosphere, respectively. We find that such protons have full and essentially immediate access from interplanetary space to the polar caps of the earth.