Obs. : 2011-03-07 Planet Ly alpha (photons/cm^2/sec) Mercury 3.826e+11 Venus 3.931e+11 Earth 4.216e+11 Mars 3.830e+11 Jupiter 3.893e+11 Saturn 4.229e+11 Uranus 3.826e+11 Neptune 3.854e+11 Pluto 3.981e+11