Obs. : 2017-05-01 Planet Ly alpha (photons/cm^2/sec) Mercury 3.806e+11 Venus 3.780e+11 Earth 3.726e+11 Mars 3.921e+11 Jupiter 3.750e+11 Saturn 3.699e+11 Uranus 3.806e+11 Neptune 3.757e+11 Pluto 3.699e+11