Obs. : 2009-11-02 Planet Ly alpha (photons/cm^2/sec) Mercury 3.651e+11 Venus 3.623e+11 Earth 3.468e+11 Mars 3.569e+11 Jupiter 3.558e+11 Saturn 3.595e+11 Uranus 3.467e+11 Neptune 3.558e+11 Pluto 3.654e+11