Obs. : 2015-01-27 Planet Ly alpha (photons/cm^2/sec) Mercury 3.722e+11 Venus 3.709e+11 Earth 3.538e+11 Mars 3.714e+11 Jupiter 3.471e+11 Saturn 3.350e+11 Uranus 3.703e+11 Neptune 3.709e+11 Pluto 3.528e+11