Obs. : 2013-08-23 Planet Ly alpha (photons/cm^2/sec) Mercury 3.966e+11 Venus 3.861e+11 Earth 4.038e+11 Mars 4.205e+11 Jupiter 4.289e+11 Saturn 3.983e+11 Uranus 4.143e+11 Neptune 4.040e+11 Pluto 4.022e+11