Obs. : 2011-10-29 Planet Ly alpha (photons/cm^2/sec) Mercury 5.046e+11 Venus 5.046e+11 Earth 4.370e+11 Mars 4.471e+11 Jupiter 4.325e+11 Saturn 4.671e+11 Uranus 4.427e+11 Neptune 4.603e+11 Pluto 5.057e+11