Obs. : 2010-08-04 Planet Ly alpha (photons/cm^2/sec) Mercury 3.760e+11 Venus 3.882e+11 Earth 3.881e+11 Mars 3.882e+11 Jupiter 3.670e+11 Saturn 3.882e+11 Uranus 3.670e+11 Neptune 3.801e+11 Pluto 3.844e+11