Obs. : 2014-03-22 Planet Ly alpha (photons/cm^2/sec) Mercury 3.990e+11 Venus 3.988e+11 Earth 4.400e+11 Mars 4.325e+11 Jupiter 4.273e+11 Saturn 4.172e+11 Uranus 4.014e+11 Neptune 3.990e+11 Pluto 3.987e+11