Obs. : 2013-11-19 Planet Ly alpha (photons/cm^2/sec) Mercury 4.119e+11 Venus 4.237e+11 Earth 4.214e+11 Mars 4.011e+11 Jupiter 4.101e+11 Saturn 4.129e+11 Uranus 4.475e+11 Neptune 4.427e+11 Pluto 4.205e+11