Obs. : 2011-10-14 Planet Ly alpha (photons/cm^2/sec) Mercury 4.398e+11 Venus 4.446e+11 Earth 4.468e+11 Mars 4.451e+11 Jupiter 4.497e+11 Saturn 4.306e+11 Uranus 4.477e+11 Neptune 4.454e+11 Pluto 4.492e+11