Obs. : 2011-09-22 Planet Ly alpha (photons/cm^2/sec) Mercury 4.598e+11 Venus 4.619e+11 Earth 4.435e+11 Mars 4.522e+11 Jupiter 4.377e+11 Saturn 4.570e+11 Uranus 4.397e+11 Neptune 4.436e+11 Pluto 4.541e+11