Obs. : 2011-07-05 Planet Ly alpha (photons/cm^2/sec) Mercury 4.161e+11 Venus 4.167e+11 Earth 4.005e+11 Mars 4.109e+11 Jupiter 4.053e+11 Saturn 4.142e+11 Uranus 3.967e+11 Neptune 3.953e+11 Pluto 4.041e+11