Obs. : 2017-07-19 Planet Ly alpha (photons/cm^2/sec) Mercury 3.568e+11 Venus 3.764e+11 Earth 3.630e+11 Mars 3.598e+11 Jupiter 3.696e+11 Saturn 3.649e+11 Uranus 3.709e+11 Neptune 3.616e+11 Pluto 3.622e+11