Obs. : 2011-04-25 Planet Ly alpha (photons/cm^2/sec) Mercury 4.467e+11 Venus 4.467e+11 Earth 4.377e+11 Mars 4.467e+11 Jupiter 4.585e+11 Saturn 4.577e+11 Uranus 4.373e+11 Neptune 4.069e+11 Pluto 4.039e+11