Obs. : 2017-02-07 Planet Ly alpha (photons/cm^2/sec) Mercury 2.286e+11 Venus 2.364e+11 Earth 2.218e+11 Mars 2.346e+11 Jupiter 2.154e+11 Saturn 2.213e+11 Uranus 2.318e+11 Neptune 2.387e+11 Pluto 2.227e+11