This graph displays the flux of high energy protons measured by GOES 11 over four days from November 2, 2003, to November 5, 2003. Credit: NOAA.
"Proton astronomy should be possible; it may also provide indirect information on inter-galactic magnetic fields."[1]
Proton astronomy per se often consists of directly or indirectly detecting the protons and deconvoluting a spatial, temporal, and spectral distribution.
“[A]t the high end of the proton energy spectrum (above ≈ 1018 eV) [the Larmor radius] deflection becomes small enough that proton astronomy becomes possible.”[2]
"The third largest solar proton event in the past thirty years took place during July 14-16, 2000, and had a significant impact on the earth's atmosphere."[3]