Obs. : 2011-07-10 Planet Ly alpha (photons/cm^2/sec) Mercury 4.055e+11 Venus 4.010e+11 Earth 3.926e+11 Mars 4.006e+11 Jupiter 4.008e+11 Saturn 4.301e+11 Uranus 3.892e+11 Neptune 3.852e+11 Pluto 4.060e+11