Obs. : 2010-02-05 Planet Ly alpha (photons/cm^2/sec) Mercury 3.688e+11 Venus 3.809e+11 Earth 3.663e+11 Mars 3.663e+11 Jupiter 3.838e+11 Saturn 3.609e+11 Uranus 3.845e+11 Neptune 3.809e+11 Pluto 3.611e+11