Obs. : 2018-09-23 Planet Ly alpha (photons/cm^2/sec) Mercury 3.282e+11 Venus 3.295e+11 Earth 3.321e+11 Mars 3.350e+11 Jupiter 3.298e+11 Saturn 3.351e+11 Uranus 3.347e+11 Neptune 3.328e+11 Pluto 3.364e+11