Obs. : 2011-08-07 Planet Ly alpha (photons/cm^2/sec) Mercury 3.929e+11 Venus 3.918e+11 Earth 3.919e+11 Mars 3.991e+11 Jupiter 3.999e+11 Saturn 4.040e+11 Uranus 3.967e+11 Neptune 3.916e+11 Pluto 3.958e+11