Obs. : 2009-06-05 Planet Ly alpha (photons/cm^2/sec) Mercury 3.576e+11 Venus 3.495e+11 Earth 3.554e+11 Mars 3.531e+11 Jupiter 3.460e+11 Saturn 3.763e+11 Uranus 3.427e+11 Neptune 3.460e+11 Pluto 3.554e+11