Obs. : 2011-11-30 Planet Ly alpha (photons/cm^2/sec) Mercury 4.755e+11 Venus 4.876e+11 Earth 4.702e+11 Mars 4.737e+11 Jupiter 4.889e+11 Saturn 4.721e+11 Uranus 5.034e+11 Neptune 5.120e+11 Pluto 4.876e+11