Obs. : 2016-09-28 Planet Ly alpha (photons/cm^2/sec) Mercury 3.919e+11 Venus 3.898e+11 Earth 3.840e+11 Mars 3.898e+11 Jupiter 3.889e+11 Saturn 3.917e+11 Uranus 3.840e+11 Neptune 3.778e+11 Pluto 3.881e+11