Obs. : 2011-01-07 Planet Ly alpha (photons/cm^2/sec) Mercury 3.624e+11 Venus 3.600e+11 Earth 3.792e+11 Mars 3.735e+11 Jupiter 3.691e+11 Saturn 3.719e+11 Uranus 3.691e+11 Neptune 3.750e+11 Pluto 3.674e+11