Obs. : 2011-10-27 Planet Ly alpha (photons/cm^2/sec) Mercury 5.001e+11 Venus 5.001e+11 Earth 4.416e+11 Mars 4.518e+11 Jupiter 4.416e+11 Saturn 4.859e+11 Uranus 4.251e+11 Neptune 4.316e+11 Pluto 4.624e+11