Obs. : 2018-04-05 Planet Ly alpha (photons/cm^2/sec) Mercury 3.544e+11 Venus 3.461e+11 Earth 3.544e+11 Mars 3.557e+11 Jupiter 3.552e+11 Saturn 3.557e+11 Uranus 3.494e+11 Neptune 3.524e+11 Pluto 3.525e+11