Obs. : 2011-12-14 Planet Ly alpha (photons/cm^2/sec) Mercury 4.468e+11 Venus 4.311e+11 Earth 4.430e+11 Mars 4.543e+11 Jupiter 4.341e+11 Saturn 4.551e+11 Uranus 4.325e+11 Neptune 4.325e+11 Pluto 4.364e+11