Obs. : 2011-10-04 Planet Ly alpha (photons/cm^2/sec) Mercury 4.334e+11 Venus 4.334e+11 Earth 4.402e+11 Mars 4.326e+11 Jupiter 4.361e+11 Saturn 4.334e+11 Uranus 4.402e+11 Neptune 4.386e+11 Pluto 4.505e+11