Obs. : 2017-04-22 Planet Ly alpha (photons/cm^2/sec) Mercury 3.636e+11 Venus 3.652e+11 Earth 3.931e+11 Mars 3.668e+11 Jupiter 3.806e+11 Saturn 3.893e+11 Uranus 3.636e+11 Neptune 3.656e+11 Pluto 3.796e+11