Obs. : 2013-11-23 Planet Ly alpha (photons/cm^2/sec) Mercury 4.225e+11 Venus 4.503e+11 Earth 3.988e+11 Mars 4.149e+11 Jupiter 3.931e+11 Saturn 4.225e+11 Uranus 4.433e+11 Neptune 4.527e+11 Pluto 4.447e+11