Obs. : 2010-04-16 Planet Ly alpha (photons/cm^2/sec) Mercury 3.871e+11 Venus 3.871e+11 Earth 3.661e+11 Mars 3.796e+11 Jupiter 3.696e+11 Saturn 3.720e+11 Uranus 3.785e+11 Neptune 3.739e+11 Pluto 3.560e+11