Obs. : 2017-04-09 Planet Ly alpha (photons/cm^2/sec) Mercury 3.978e+11 Venus 3.969e+11 Earth 3.668e+11 Mars 3.804e+11 Jupiter 3.595e+11 Saturn 3.713e+11 Uranus 3.978e+11 Neptune 3.902e+11 Pluto 3.739e+11