Obs. : 2013-07-30 Planet Ly alpha (photons/cm^2/sec) Mercury 4.117e+11 Venus 4.023e+11 Earth 3.915e+11 Mars 4.117e+11 Jupiter 4.126e+11 Saturn 4.079e+11 Uranus 3.893e+11 Neptune 3.820e+11 Pluto 3.915e+11