Obs. : 2015-02-01 Planet Ly alpha (photons/cm^2/sec) Mercury 5.179e+11 Venus 5.390e+11 Earth 5.532e+11 Mars 5.529e+11 Jupiter 5.528e+11 Saturn 5.131e+11 Uranus 5.630e+11 Neptune 5.390e+11 Pluto 5.082e+11