Obs. : 2014-09-13 Planet Ly alpha (photons/cm^2/sec) Mercury 4.080e+11 Venus 4.098e+11 Earth 3.980e+11 Mars 4.031e+11 Jupiter 4.067e+11 Saturn 4.048e+11 Uranus 3.982e+11 Neptune 3.963e+11 Pluto 3.940e+11