Obs. : 2013-01-03 Planet Ly alpha (photons/cm^2/sec) Mercury 4.215e+11 Venus 4.159e+11 Earth 4.460e+11 Mars 4.370e+11 Jupiter 4.498e+11 Saturn 4.064e+11 Uranus 4.581e+11 Neptune 4.536e+11 Pluto 4.215e+11