Obs. : 2009-11-14 Planet Ly alpha (photons/cm^2/sec) Mercury 3.613e+11 Venus 3.498e+11 Earth 3.540e+11 Mars 3.438e+11 Jupiter 3.651e+11 Saturn 3.371e+11 Uranus 3.610e+11 Neptune 3.630e+11 Pluto 3.686e+11