Obs. : 2013-03-10 Planet Ly alpha (photons/cm^2/sec) Mercury 4.052e+11 Venus 4.052e+11 Earth 4.476e+11 Mars 4.009e+11 Jupiter 4.013e+11 Saturn 4.453e+11 Uranus 3.999e+11 Neptune 4.055e+11 Pluto 4.234e+11