Obs. : 2017-11-29 Planet Ly alpha (photons/cm^2/sec) Mercury 3.726e+11 Venus 3.755e+11 Earth 3.618e+11 Mars 3.768e+11 Jupiter 3.766e+11 Saturn 3.726e+11 Uranus 3.587e+11 Neptune 3.639e+11 Pluto 3.707e+11