Obs. : 2010-05-08 Planet Ly alpha (photons/cm^2/sec) Mercury 3.835e+11 Venus 3.830e+11 Earth 3.850e+11 Mars 3.762e+11 Jupiter 3.837e+11 Saturn 3.770e+11 Uranus 3.837e+11 Neptune 3.784e+11 Pluto 3.818e+11