Obs. : 2008-05-30 Planet Ly alpha (photons/cm^2/sec) Mercury 3.509e+11 Venus 3.494e+11 Earth 3.423e+11 Mars 3.507e+11 Jupiter 3.400e+11 Saturn 3.501e+11 Uranus 3.459e+11 Neptune 3.409e+11 Pluto 3.423e+11