Obs. : 2013-09-01 Planet Ly alpha (photons/cm^2/sec) Mercury 4.326e+11 Venus 4.337e+11 Earth 4.024e+11 Mars 4.049e+11 Jupiter 4.056e+11 Saturn 4.281e+11 Uranus 4.017e+11 Neptune 4.004e+11 Pluto 4.040e+11