Obs. : 2013-01-15 Planet Ly alpha (photons/cm^2/sec) Mercury 4.578e+11 Venus 4.582e+11 Earth 4.478e+11 Mars 4.482e+11 Jupiter 4.369e+11 Saturn 4.660e+11 Uranus 4.349e+11 Neptune 4.478e+11 Pluto 4.582e+11