Obs. : 2009-06-09 Planet Ly alpha (photons/cm^2/sec) Mercury 3.553e+11 Venus 3.467e+11 Earth 3.541e+11 Mars 3.539e+11 Jupiter 3.463e+11 Saturn 3.631e+11 Uranus 3.429e+11 Neptune 3.463e+11 Pluto 3.560e+11