Obs. : 2016-03-09 Planet Ly alpha (photons/cm^2/sec) Mercury 2.220e+11 Venus 2.227e+11 Earth 2.271e+11 Mars 2.265e+11 Jupiter 2.292e+11 Saturn 2.250e+11 Uranus 2.213e+11 Neptune 2.220e+11 Pluto 2.235e+11