Obs. : 2015-12-16 Planet Ly alpha (photons/cm^2/sec) Mercury 4.246e+11 Venus 4.017e+11 Earth 4.464e+11 Mars 4.137e+11 Jupiter 4.327e+11 Saturn 4.040e+11 Uranus 4.397e+11 Neptune 4.401e+11 Pluto 4.246e+11