Obs. : 2010-07-09 Planet Ly alpha (photons/cm^2/sec) Mercury 3.773e+11 Venus 3.769e+11 Earth 3.780e+11 Mars 3.922e+11 Jupiter 3.750e+11 Saturn 3.922e+11 Uranus 3.730e+11 Neptune 3.728e+11 Pluto 3.850e+11