Obs. : 2010-12-22 Planet Ly alpha (photons/cm^2/sec) Mercury 3.803e+11 Venus 3.750e+11 Earth 3.788e+11 Mars 3.823e+11 Jupiter 3.694e+11 Saturn 3.730e+11 Uranus 3.694e+11 Neptune 3.762e+11 Pluto 3.823e+11