Obs. : 2017-12-02 Planet Ly alpha (photons/cm^2/sec) Mercury 3.775e+11 Venus 3.728e+11 Earth 3.526e+11 Mars 3.606e+11 Jupiter 3.671e+11 Saturn 3.775e+11 Uranus 3.547e+11 Neptune 3.615e+11 Pluto 3.748e+11