Obs. : 2012-01-29 Planet Ly alpha (photons/cm^2/sec) Mercury 4.305e+11 Venus 4.228e+11 Earth 4.338e+11 Mars 4.307e+11 Jupiter 4.262e+11 Saturn 4.222e+11 Uranus 4.225e+11 Neptune 4.263e+11 Pluto 4.262e+11