Obs. : 2018-06-08 Planet Ly alpha (photons/cm^2/sec) Mercury 3.300e+11 Venus 3.309e+11 Earth 3.281e+11 Mars 3.188e+11 Jupiter 3.295e+11 Saturn 3.213e+11 Uranus 3.215e+11 Neptune 3.187e+11 Pluto 3.200e+11