Obs. : 2010-07-10 Planet Ly alpha (photons/cm^2/sec) Mercury 3.776e+11 Venus 3.755e+11 Earth 3.790e+11 Mars 3.908e+11 Jupiter 3.720e+11 Saturn 3.908e+11 Uranus 3.720e+11 Neptune 3.734e+11 Pluto 3.903e+11