Obs. : 2016-12-06 Planet Ly alpha (photons/cm^2/sec) Mercury 3.420e+11 Venus 3.408e+11 Earth 3.333e+11 Mars 3.400e+11 Jupiter 3.407e+11 Saturn 3.415e+11 Uranus 3.337e+11 Neptune 3.392e+11 Pluto 3.408e+11