Obs. : 2013-10-22 Planet Ly alpha (photons/cm^2/sec) Mercury 4.144e+11 Venus 4.121e+11 Earth 4.370e+11 Mars 4.297e+11 Jupiter 4.281e+11 Saturn 4.189e+11 Uranus 4.348e+11 Neptune 4.275e+11 Pluto 4.123e+11