Obs. : 2012-03-31 Planet Ly alpha (photons/cm^2/sec) Mercury 4.266e+11 Venus 4.205e+11 Earth 4.259e+11 Mars 4.202e+11 Jupiter 4.215e+11 Saturn 4.306e+11 Uranus 4.247e+11 Neptune 4.298e+11 Pluto 4.267e+11