Obs. : 2010-04-13 Planet Ly alpha (photons/cm^2/sec) Mercury 3.885e+11 Venus 3.885e+11 Earth 3.680e+11 Mars 3.807e+11 Jupiter 3.764e+11 Saturn 3.747e+11 Uranus 3.810e+11 Neptune 3.708e+11 Pluto 3.637e+11