Obs. : 2014-09-20 Planet Ly alpha (photons/cm^2/sec) Mercury 4.262e+11 Venus 4.167e+11 Earth 4.015e+11 Mars 4.285e+11 Jupiter 4.140e+11 Saturn 4.271e+11 Uranus 4.038e+11 Neptune 4.039e+11 Pluto 4.232e+11