Obs. : 2018-01-31 Planet Ly alpha (photons/cm^2/sec) Mercury 3.455e+11 Venus 3.461e+11 Earth 3.387e+11 Mars 3.433e+11 Jupiter 3.427e+11 Saturn 3.444e+11 Uranus 3.383e+11 Neptune 3.472e+11 Pluto 3.450e+11