Obs. : 2010-12-11 Planet Ly alpha (photons/cm^2/sec) Mercury 3.783e+11 Venus 3.658e+11 Earth 3.801e+11 Mars 3.726e+11 Jupiter 3.811e+11 Saturn 3.667e+11 Uranus 3.811e+11 Neptune 3.825e+11 Pluto 3.726e+11