Obs. : 2010-01-01 Planet Ly alpha (photons/cm^2/sec) Mercury 3.802e+11 Venus 3.705e+11 Earth 3.564e+11 Mars 3.553e+11 Jupiter 3.820e+11 Saturn 3.511e+11 Uranus 3.716e+11 Neptune 3.820e+11 Pluto 3.705e+11