Obs. : 2010-09-11 Planet Ly alpha (photons/cm^2/sec) Mercury 3.765e+11 Venus 3.808e+11 Earth 3.772e+11 Mars 3.808e+11 Jupiter 3.747e+11 Saturn 3.816e+11 Uranus 3.747e+11 Neptune 3.772e+11 Pluto 3.820e+11