Obs. : 2011-09-01 Planet Ly alpha (photons/cm^2/sec) Mercury 4.247e+11 Venus 4.236e+11 Earth 4.268e+11 Mars 4.292e+11 Jupiter 4.267e+11 Saturn 4.210e+11 Uranus 4.253e+11 Neptune 4.258e+11 Pluto 4.261e+11