Obs. : 2011-11-29 Planet Ly alpha (photons/cm^2/sec) Mercury 4.847e+11 Venus 4.972e+11 Earth 4.652e+11 Mars 4.752e+11 Jupiter 4.810e+11 Saturn 4.700e+11 Uranus 5.010e+11 Neptune 5.176e+11 Pluto 4.972e+11