Obs. : 2014-02-09 Planet Ly alpha (photons/cm^2/sec) Mercury 3.946e+11 Venus 4.246e+11 Earth 4.027e+11 Mars 4.449e+11 Jupiter 3.987e+11 Saturn 4.401e+11 Uranus 3.943e+11 Neptune 3.946e+11 Pluto 4.246e+11