Obs. : 2017-08-12 Planet Ly alpha (photons/cm^2/sec) Mercury 3.477e+11 Venus 3.678e+11 Earth 3.633e+11 Mars 3.543e+11 Jupiter 3.573e+11 Saturn 3.652e+11 Uranus 3.698e+11 Neptune 3.654e+11 Pluto 3.623e+11