Obs. : 2014-04-09 Planet Ly alpha (photons/cm^2/sec) Mercury 3.838e+11 Venus 3.851e+11 Earth 3.551e+11 Mars 3.547e+11 Jupiter 3.634e+11 Saturn 3.586e+11 Uranus 3.827e+11 Neptune 3.854e+11 Pluto 3.773e+11