Obs. : 2011-07-03 Planet Ly alpha (photons/cm^2/sec) Mercury 4.071e+11 Venus 4.122e+11 Earth 3.993e+11 Mars 4.110e+11 Jupiter 4.069e+11 Saturn 3.983e+11 Uranus 3.966e+11 Neptune 3.961e+11 Pluto 4.013e+11