Obs. : 2010-08-22 Planet Ly alpha (photons/cm^2/sec) Mercury 3.756e+11 Venus 3.771e+11 Earth 3.689e+11 Mars 3.763e+11 Jupiter 3.952e+11 Saturn 3.763e+11 Uranus 3.929e+11 Neptune 3.720e+11 Pluto 3.739e+11