Obs. : 2011-08-04 Planet Ly alpha (photons/cm^2/sec) Mercury 3.976e+11 Venus 3.907e+11 Earth 4.005e+11 Mars 3.956e+11 Jupiter 4.068e+11 Saturn 4.046e+11 Uranus 4.049e+11 Neptune 4.027e+11 Pluto 3.975e+11