Obs. : 2010-05-12 Planet Ly alpha (photons/cm^2/sec) Mercury 3.773e+11 Venus 3.790e+11 Earth 3.687e+11 Mars 3.742e+11 Jupiter 3.767e+11 Saturn 3.655e+11 Uranus 3.767e+11 Neptune 3.717e+11 Pluto 3.687e+11