Obs. : 2015-01-09 Planet Ly alpha (photons/cm^2/sec) Mercury 4.221e+11 Venus 4.221e+11 Earth 4.440e+11 Mars 4.284e+11 Jupiter 4.480e+11 Saturn 4.154e+11 Uranus 4.472e+11 Neptune 4.332e+11 Pluto 4.097e+11