Obs. : 2011-06-25 Planet Ly alpha (photons/cm^2/sec) Mercury 3.920e+11 Venus 3.975e+11 Earth 4.182e+11 Mars 4.035e+11 Jupiter 4.154e+11 Saturn 4.172e+11 Uranus 4.178e+11 Neptune 4.206e+11 Pluto 4.158e+11