Obs. : 2015-12-18 Planet Ly alpha (photons/cm^2/sec) Mercury 4.227e+11 Venus 4.351e+11 Earth 4.427e+11 Mars 4.414e+11 Jupiter 4.423e+11 Saturn 4.237e+11 Uranus 4.366e+11 Neptune 4.332e+11 Pluto 4.227e+11