Obs. : 2008-11-08 Planet Ly alpha (photons/cm^2/sec) Mercury 3.542e+11 Venus 3.595e+11 Earth 3.538e+11 Mars 3.527e+11 Jupiter 3.594e+11 Saturn 3.435e+11 Uranus 3.512e+11 Neptune 3.569e+11 Pluto 3.595e+11