Obs. : 2011-08-02 Planet Ly alpha (photons/cm^2/sec) Mercury 4.020e+11 Venus 3.910e+11 Earth 4.051e+11 Mars 3.898e+11 Jupiter 4.072e+11 Saturn 4.024e+11 Uranus 4.095e+11 Neptune 4.078e+11 Pluto 4.023e+11