Obs. : 2011-07-29 Planet Ly alpha (photons/cm^2/sec) Mercury 4.044e+11 Venus 4.023e+11 Earth 4.113e+11 Mars 3.976e+11 Jupiter 3.960e+11 Saturn 3.995e+11 Uranus 3.959e+11 Neptune 4.061e+11 Pluto 4.084e+11