Obs. : 2011-10-10 Planet Ly alpha (photons/cm^2/sec) Mercury 4.082e+11 Venus 4.082e+11 Earth 4.259e+11 Mars 4.180e+11 Jupiter 4.253e+11 Saturn 4.082e+11 Uranus 4.223e+11 Neptune 4.187e+11 Pluto 4.248e+11