Obs. : 2014-02-16 Planet Ly alpha (photons/cm^2/sec) Mercury 4.866e+11 Venus 4.712e+11 Earth 4.223e+11 Mars 4.176e+11 Jupiter 4.205e+11 Saturn 4.242e+11 Uranus 4.535e+11 Neptune 4.826e+11 Pluto 4.545e+11