Obs. : 2010-10-17 Planet Ly alpha (photons/cm^2/sec) Mercury 3.636e+11 Venus 3.727e+11 Earth 3.805e+11 Mars 3.727e+11 Jupiter 3.785e+11 Saturn 3.517e+11 Uranus 3.785e+11 Neptune 3.798e+11 Pluto 3.851e+11