Obs. : 2014-09-17 Planet Ly alpha (photons/cm^2/sec) Mercury 4.256e+11 Venus 4.181e+11 Earth 4.044e+11 Mars 4.287e+11 Jupiter 4.163e+11 Saturn 4.291e+11 Uranus 4.084e+11 Neptune 4.037e+11 Pluto 4.191e+11