Obs. : 2011-08-03 Planet Ly alpha (photons/cm^2/sec) Mercury 4.010e+11 Venus 4.004e+11 Earth 4.066e+11 Mars 4.028e+11 Jupiter 4.173e+11 Saturn 4.056e+11 Uranus 4.181e+11 Neptune 4.135e+11 Pluto 4.018e+11