Obs. : 2013-08-29 Planet Ly alpha (photons/cm^2/sec) Mercury 4.381e+11 Venus 4.145e+11 Earth 4.015e+11 Mars 4.295e+11 Jupiter 4.240e+11 Saturn 4.068e+11 Uranus 3.989e+11 Neptune 4.008e+11 Pluto 4.028e+11