Obs. : 2010-03-31 Planet Ly alpha (photons/cm^2/sec) Mercury 3.848e+11 Venus 3.848e+11 Earth 3.661e+11 Mars 3.707e+11 Jupiter 3.737e+11 Saturn 3.628e+11 Uranus 3.807e+11 Neptune 3.681e+11 Pluto 3.610e+11