Obs. : 2011-04-11 Planet Ly alpha (photons/cm^2/sec) Mercury 4.451e+11 Venus 4.517e+11 Earth 4.190e+11 Mars 4.451e+11 Jupiter 4.451e+11 Saturn 4.190e+11 Uranus 4.539e+11 Neptune 4.582e+11 Pluto 4.386e+11