Obs. : 2008-11-22 Planet Ly alpha (photons/cm^2/sec) Mercury 3.508e+11 Venus 3.542e+11 Earth 3.457e+11 Mars 3.599e+11 Jupiter 3.525e+11 Saturn 3.353e+11 Uranus 3.464e+11 Neptune 3.507e+11 Pluto 3.505e+11