Obs. : 2015-08-11 Planet Ly alpha (photons/cm^2/sec) Mercury 4.004e+11 Venus 4.130e+11 Earth 4.399e+11 Mars 4.490e+11 Jupiter 4.130e+11 Saturn 4.214e+11 Uranus 4.502e+11 Neptune 4.490e+11 Pluto 4.345e+11