Obs. : 2010-04-14 Planet Ly alpha (photons/cm^2/sec) Mercury 3.915e+11 Venus 3.915e+11 Earth 3.679e+11 Mars 3.834e+11 Jupiter 3.759e+11 Saturn 3.742e+11 Uranus 3.817e+11 Neptune 3.769e+11 Pluto 3.638e+11