Obs. : 2014-04-30 Planet Ly alpha (photons/cm^2/sec) Mercury 4.604e+11 Venus 4.414e+11 Earth 4.110e+11 Mars 4.112e+11 Jupiter 4.270e+11 Saturn 4.121e+11 Uranus 4.472e+11 Neptune 4.242e+11 Pluto 4.147e+11