Obs. : 2010-08-16 Planet Ly alpha (photons/cm^2/sec) Mercury 3.718e+11 Venus 3.750e+11 Earth 3.722e+11 Mars 3.750e+11 Jupiter 3.764e+11 Saturn 3.716e+11 Uranus 3.764e+11 Neptune 3.721e+11 Pluto 3.724e+11