Obs. : 2011-02-23 Planet Ly alpha (photons/cm^2/sec) Mercury 3.958e+11 Venus 3.880e+11 Earth 3.630e+11 Mars 3.958e+11 Jupiter 3.946e+11 Saturn 3.626e+11 Uranus 3.978e+11 Neptune 3.958e+11 Pluto 3.835e+11