Obs. : 2013-08-12 Planet Ly alpha (photons/cm^2/sec) Mercury 3.605e+11 Venus 3.683e+11 Earth 3.770e+11 Mars 3.674e+11 Jupiter 3.674e+11 Saturn 3.912e+11 Uranus 3.657e+11 Neptune 3.709e+11 Pluto 3.811e+11